Mary Berry Potato and Onion Gratin
Mary Berry’s Potato and Onion Gratin is a classic French-inspired dish featuring thinly sliced potatoes and onions layered and baked in a creamy, cheesy sauce. The gratin is baked until golden and bubbling, with the potatoes becoming tender and absorbing the rich flavors of the cream, cheese, and onions. It’s a wonderful side dish that pairs well with a variety of mains or can even be enjoyed on its own.
- Prep Time: 15
- Cook Time: 65
- Total Time: 1 hour 20 minutes
- Yield: 4
- Category: Side Dish
- Method: Baking
- Cuisine: French
Ingredients
- Potatoes (800g, thinly sliced): Waxy potatoes like Maris Piper or Yukon Gold work best for a creamy texture.
- Onions (2 medium, thinly sliced): Adds a sweet, savory depth to the dish.
- Double cream (300ml): Creates a rich, velvety sauce that binds the potatoes and onions together.
- Cheddar cheese (100g, grated): Adds flavor and creates a golden, crispy top.
- Butter (25g): Used for greasing the dish and adds richness to the gratin.
- Fresh thyme (1 tablespoon, chopped): Provides an earthy, aromatic flavor to the dish.
- Salt and pepper (to taste): Essential for seasoning the dish.
Instructions
Step 1: Preheat the oven
Preheat your oven to 180°C (350°F) and butter an ovenproof baking dish to prevent sticking.
Step 2: Slice the potatoes and onions
Using a mandoline or sharp knife, thinly slice the potatoes and onions. Aim for uniform slices to ensure even cooking.
Step 3: Prepare the cream mixture
In a small saucepan, heat the double cream gently over low heat. Stir in the fresh thyme, salt, and pepper. Heat the mixture just until warmed through, then remove from heat.
Step 4: Layer the potatoes and onions
Start by placing a layer of sliced potatoes at the bottom of the buttered baking dish, followed by a layer of onions. Repeat the layers until all the potatoes and onions are used up, finishing with a layer of potatoes on top.
Step 5: Add the cream and cheese
Pour the warm cream mixture evenly over the layered potatoes and onions, making sure it’s well distributed. Sprinkle the grated cheddar cheese over the top to create a delicious, golden crust.
Step 6: Bake the gratin
Cover the dish with foil and bake in the preheated oven for 45 minutes. After 45 minutes, remove the foil and bake for another 20-25 minutes, or until the top is golden and the potatoes are tender when pierced with a knife.
Step 7: Serve
Once the gratin is golden and bubbling, remove it from the oven and allow it to rest for 5 minutes before serving. This gives the flavors time to meld and the gratin to set slightly.