A gratin is a delicious baked dish that is topped with cheese or breadcrumbs. But what exactly makes a gratin a gratin? There are a few key requirements for a dish to be considered a true gratin.
Origin of Gratin
The word “gratin” comes from the French word “grater” meaning “to scrape or grate”. This refers to the topping or crust that forms on top of the gratin as it bakes in the oven.
The earliest gratins originated in France, where local ingredients like potatoes, cheese, cream and breadcrumbs were baked into comforting, hearty dishes. Over time, the concept spread to become popular around Europe and eventually, the rest of the world.
Essential Components of a Gratin
While gratins come in many regional and seasonal varieties, they generally share a few key components:
Baked Dish
A gratin requires a shallow baking dish to allow the topping to crisp and brown. Anything from a cast iron pan to a porcelain gratin dish will work.
Main Ingredient
The base of the gratin relies on a starchy ingredient that softens and absorbs liquid as it bakes. Common options are potatoes, pasta, bread, rice or vegetables like cauliflower or zucchini.
Sauce or Binder
A sauce or creamy binder ensures the gratin ingredients hold together. Milk, cream, broth, cheese or egg mixtures are often used.
Topping
The topping provides texture and flavor contrast. Breadcrumbs, cheese or a combination are traditional gratin toppings.
High Heat
Gratins are baked at a high temperature, usually 375°F to 400°F, so the topping gets nicely browned and crusty.
Common Types of Gratins
There are countless varieties of gratins, but some of the most classic and popular include:
Potato Gratin
Thinly sliced potatoes baked in cream and cheese is a quintessential gratin dish. Other vegetables like celery root or sweet potatoes can also be used.
Pasta Gratin
Short pasta shapes like macaroni or ziti baked with sauce, cheese and sometimes meat or vegetables.
Green Bean Gratin
Green beans in a creamy cheese sauce topped with crispy fried onions is a holiday favorite.
Bread or Rice Gratin
Stale bread or cooked rice provides a neutral base that absorbs other gratin flavors.
Seafood Gratin
Shellfish like shrimp, crab or lobster baked in a garlic cream sauce and cheese topping.
Vegetable Gratin
Almost any vegetable, or combination of veggies, can be sliced or pureed into a gratin like cauliflower, zucchini, mushrooms or squash.
The Science Behind a Perfect Gratin
There is some culinary science that goes into making the ultimate crispy, flavorful gratin.
Cooking Vessel
A shallow pan ensures a high ratio of crispy topping to tender interior. Gratin dishes or cast iron skillets work well.
Texture
Uniformly thinly slicing potatoes or other vegetables ensures even cooking and the right ratio of tender inside to crispy outside.
Layering
Building gratins in layers results in more even baking and better flavor distribution. Also creates visual appeal when served.
Fat Content
Including dairy ingredients like cream, milk or cheese adds fat which conducts heat and helps form a crispy crust.
Browning Reactions
High heat causes the Maillard reaction and caramelization, which give appealing color, aromas, and depth of flavor.
Tips for the Perfect Gratin
Follow these tips for gratins with the ideal golden crust and tender, creamy interior:
– Use the right baking vessel – shallow surface area is key
– Preheat oven to at least 375°F
– Slice or shred ingredients to uniform sizes
– Layer ingredients like lasagna, don’t overstuff
– Add a binder like béchamel, cheese sauce or creamy mixture
– Top with breadcrumbs, cheese or a combination
– Bake on middle or top rack until browned and bubbly
– Let rest 10 minutes before serving
Gratin Ingredient Substitutions
Gratins are highly adaptable to work with the ingredients you have on hand. Consider these substitutions:
Base Ingredients
– Potatoes = sweet potatoes, celery root, zucchini, pumpkin, winter squash, etc
– Pasta = rice, bread cubes or torn bread pieces
– Cheese = eggs, chickpea flour, nutritional yeast
Binders
– Heavy cream = milk, half and half, creme fraiche, yogurt
– Butter = oil
– Flour = cornstarch, arrowroot
Cheese
– Hard grating cheese (parmesan, etc) = panko breadcrumbs
– Soft melting cheese (brie, etc) = cream cheese, goat cheese
Toppings
– Breadcrumbs = crushed crackers, oats, nuts or seeds
– Cheese = mashed potatoes, pureed cauliflower
How to Make Potatoes Gratin
Potato gratin is one of the most beloved, classic versions. Follow this recipe for the ultimate creamy, crispy potato gratin.
Ingredients
– 3 lbs russet or Yukon gold potatoes, peeled and thinly sliced
– 3 cloves garlic, minced
– 3 tbsps butter
– 3 tbsps all-purpose flour
– 2 cups milk
– 1 cup heavy cream
– 1⁄2 tsp nutmeg
– Salt and pepper to taste
– 1 1⁄2 cups grated Gruyere cheese
Instructions
- Preheat oven to 375°F. Butter a 3-qt baking dish.
- In a saucepan, melt butter over medium heat. Add garlic and cook 1 minute until fragrant. Whisk in flour and cook 2 minutes.
- While whisking, slowly add milk and cream. Bring to a simmer and cook 5 minutes until thickened to a creamy sauce consistency.
- Season sauce with nutmeg, salt and pepper.
- Add 1 cup of the grated Gruyere cheese and stir until melted and smooth.
- Layer 1/3 of the sliced potatoes in the prepared baking dish. Top with 1/3 of the sauce. Repeat layers twice more, ending with sauce.
- Top with remaining 1/2 cup grated cheese.
- Bake 45-55 minutes until potatoes are fork tender and top is browned and crusty.
- Let rest 10 minutes before serving.
Tips
– For more flavor, use a combination of milk and cream. All cream makes it overly rich.
– The key is thin, even potato slices for tender insides and crispy edges. Use a mandoline for perfect slices.
– Check after 45 minutes, then continue baking until potatoes are fall-apart tender when pierced.
– Letting the gratin rest before serving allows it to firm up a bit for better slicing.
How to Make Butternut Squash Gratin
This vegetable gratin highlights creamy, sweet butternut squash baked with tangy goat cheese.
Ingredients
– 3 pound butternut squash, peeled, seeded and sliced 1/4-inch thick (about 6 cups)
– 2 tbsp olive oil
– 1⁄4 cup thinly sliced shallot
– 2 garlic cloves, minced
– 1 tbsp chopped fresh thyme leaves
– 1⁄4 cup dry white wine or vegetable broth
– 1⁄2 cup heavy cream
– 1⁄3 cup goat cheese
– 1⁄4 cup grated parmesan
– Salt and pepper to taste
Instructions
- Preheat oven to 400°F. Butter a 2-qt baking dish.
- On a baking sheet, toss butternut squash slices with 1 tbsp oil. Roast 15 minutes until beginning to soften.
- Meanwhile, heat remaining 1 tbsp oil in a skillet over medium heat. Add shallots and cook 2 minutes until softened. Add garlic and thyme and cook 1 minute until fragrant.
- Deglaze pan with white wine, scraping any browned bits from the bottom. Simmer until reduced by half. Remove from heat and stir in cream. Season with salt and pepper.
- In the prepared baking dish, layer half the roasted squash slices. Top with half the shallot cream sauce. Sprinkle with half the goat cheese and parmesan.
- Repeat layers once more and top with any remaining parmesan.
- Bake 25-30 minutes until bubbly and top is browned. Let cool 10 minutes before serving.
Tips
– Roast butternut squash first to release moisture that would otherwise make the gratin watery.
– A combination of flavorful cheeses like goat and parmesan give the best texture and taste.
– For convenience, prep this gratin up to the baking step 1 day ahead. Refrigerate and bake just before serving.
How to Make Easy Bread Gratin
Stale bread pieces make an easy, no-fuss base for this budget-friendly gratin.
Ingredients
– 6 cups cubed day-old French bread (1-inch cubes)
– 3 cups shredded cheese (cheddar, Gruyere, fontina or a blend)
– 3 cups warm milk
– 4 eggs
– 1⁄2 tsp dry mustard
– 1⁄2 tsp salt
– 1⁄4 tsp black pepper
– Pinch nutmeg
– 2 tbsp fresh parsley, chopped
Instructions
- Preheat oven to 375°F. Butter a 3-qt baking dish.
- Arrange half the bread cubes in the prepared baking dish. Top with half the shredded cheese.
- In a bowl, whisk together milk, eggs and seasonings until well combined.
- Pour half the milk mixture over the bread and cheese. Top with remaining bread and cheese. Pour over remaining milk mixture.
- Bake uncovered 35-40 minutes until puffed and top is browned. Let cool 10 minutes before serving.
- Garnish with fresh chopped parsley.
Tips
– Day old bread works best. Fresh bread won’t soak up the custard.
– A combination of cheeses gives the best flavor. Try cheddar, gruyere and parmesan.
– For best texture, make sure bread soaks up the liquid during baking. Check halfway and add more milk if needed.
Common Questions About Gratins
Here are answers to some frequently asked questions about making perfect gratins:
Should the baking dish be covered or uncovered?
Gratins are typically uncovered during baking to allow moisture to evaporate and the surface to brown. The exception would be using bread or panko crumbs, which can dry out if baked uncovered.
What temperature should I bake the gratin?
Aim for 375°F to 400°F to sufficiently brown the topping and cook through the interior. Lower temperatures may lead to a soggy texture.
How will I know when the gratin is finished baking?
Test for doneness by piercing the center with a knife to check if the interior is cooked through. The top should be nicely browned.
Can I prepare a gratin in advance?
Yes, assemble the gratin completely then cover and refrigerate up to 2 days before baking. Add 15-20 extra minutes to the baking time.
Can I freeze a gratin?
Most gratins freeze well for up to 3 months. Allow to thaw in the refrigerator then reheat in a 375°F oven until hot and bubbling.
What is the best cheese for gratin?
Gruyere is a classic choice for its nutty flavor and melty texture. Cheddar, fontina, gouda and parmesan also work well. Use a combo for complex flavor.
Conclusion
A gratin really comes down to a simple formula: take a starchy base ingredient, cover it with a flavorful creamy sauce, add cheese or breadcrumbs on top, and bake until bubbling and golden. While gratins require some time and effort, the crispy crown and rich interior make it well worth it. Experiment with different ingredient combinations and serve gratins as a comforting side dish or even a vegetarian main course. Whatever you bake, embracing the classic gratin method ensures delicious results.