Gratin is a French dish made from sliced potatoes baked in milk or cream. The term ombré translates from French as “shading.” This technique creates a smooth transition between colors in the vegetable pattern, giving the dish an aesthetically pleasing appearance. By using three sets of ingredients (for the base, vegetables, and sauce) in this method of baking seasonal vegetables, the product composition of the gratin with phyllo dough achieves a festive perfection, despite its simple components.
For this French gratin in the oven, you will need three groups of ingredients.
Ingredients for the base: store-bought phyllo dough – 16 sheets; butter – 120 g.
Ingredients for the vegetables: potatoes – 1 kg; sweet potatoes – 2; pumpkin – 900 g; beets – 2; Gruyère cheese (hard, with a dense structure, melts easily) – 800 g; salt – a pinch.
Ingredients for the sauce: eggs – 3; butter – 3 tablespoons; shallots – 30 g; garlic – 8 cloves; mustard – 4 tablespoons; bay leaves – 8; thyme (dried herb) – 2 tablespoons; nutmeg (ground) – a pinch; salt – 1.5 teaspoons; black pepper (ground) – a pinch.
Preparation
- Start by making the fragrant vegetable and cheese casserole with the sauce. In a large pot over medium heat, melt the butter, add the chopped shallots, garlic, and whole black peppercorns. After the onions soften (about 5 minutes), add the other spices: bay leaves, thyme, nutmeg, pepper, and salt. Simmer the sauce on low heat for 20 minutes until it thickens slightly, stirring occasionally.
- Strain the seasoned cream through a fine sieve into a large bowl (you should have about 3 cups) and pour it back into the pot where it was cooked. In the emptied bowl, whisk the egg yolks with the cream. Do this gradually: first beat the yolks, then add a spoonful of warm cream several times, whisking together. Reserve one cup of cream for serving the dish.
- Slice the unpeeled sweet potatoes thinly (you can substitute regular potatoes), season with salt and pepper, and mix them in the pot with the warm cream.
- Layer the gratin to create the ombré effect and form a delicate creamy vegetable gratin. Cut the peeled beets in half, thinly slice them with a sharp knife, season with salt and pepper, and arrange them in two even layers in a greased baking dish (the slices should slightly overlap), evenly sprinkling grated cheese on top (this will be about one cup and a third).
- Place the seasoned potatoes on top of the beets and cheese in two or three even layers, pressing down to avoid air pockets. Sprinkle the potatoes with the same amount of grated cheese.
- Season the chopped pumpkin with salt and pepper, layer it over the potatoes and cheese in two layers, and sprinkle with grated cheese. If you have pumpkin, you might also enjoy this .
- On top of the pumpkin and cheese, layer the potatoes in two or three layers and pour the remaining creamy mixture over the vegetables.
- Place the prepared ombré gratin with potatoes, sweet potatoes, pumpkin, and beets on the middle rack of the oven above a baking sheet to catch any drips. Bake the gratin with the creamy sauce for one hour in a preheated oven at 190°C (375°F) until the vegetables are tender.
- Brush the stacked layers of phyllo dough with melted butter (crumple them into folds) – create 8 strips.
- After an hour, remove the vegetables from the oven, cover them with the crumpled phyllo strips, brush the top layer with melted butter, and bake until golden brown for another half hour, increasing the heat to 220°C (428°F).
- Before slicing, let the aromatic gratin cool for half an hour to allow the liquid to absorb and make it easier to cut into pieces.
- Meanwhile, heat the remaining cream over medium heat for 2 minutes, season with salt and pepper, and serve alongside the dish.
Cooks who know how to prepare this delicacy confirm that this ombré gratin with potatoes, sweet potatoes, pumpkin, and beets is worth the effort and time – especially when it comes to a dish for a family dinner or festive table. As an alternative to the classic vegetable casserole, try the .
Tips for the Perfect Ombré Gratin
- To ensure that hard root vegetables bake to a tender, creamy state, slice them very thinly – a vegetable peeler makes this easy.
- You can prepare the sweet potatoes and pumpkin in advance, but slice the regular potatoes and beets just before assembling to prevent the potatoes from darkening and the beets from becoming mushy. Another option is this .
