Onion gratin is a simple and super tasty vegetarian dish. The onions are first blanched in water and vinegar, to make them tender and much more digestible, sprinkled with Parmesan and breadcrumbs, then baked in the oven until the surface is crisp and golden. The end result is a light and satisfying side dish, perfect to be served both hot and at room temperature as an accompaniment to a roast veal or a mixed grill of meat. In combination with cold cuts and cheeses, they also lend themselves to being enjoyed at aperitif time. Find out how to make them by following our recipe step by step.
Ready in: 40 MINUTES
FOR 4 PEOPLE
% Daily Value*
Total Fat 16.6g 21%, Saturated Fat 2.8g 14%, Cholesterol 4mg 1%, Sodium 160mg 7%, Total Carbohydrate 100.8g 37%, Dietary Fiber 21.9g 78%, Total Sugars 43g, Protein 14g, Vitamin D 0mcg 0%, Calcium 293mg 23%, Iron 3mg 14%, Potassium 1480mg 31%
*The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calorie a day is used for general nutrition advice.
ONIONS 1 kg • 42 kcal
BREAD CRUMBS as required • 21 kcal
APPLE VINEGAR 100 ml
SALT as required • 0 kcal
GRATED PARMESAN as required • 21 kcal
PEPPER as required • 79 kcal
EXTRA VIRGIN OLIVE OIL as required • 29 kcal
The calories refer to 100 grams of the product
How to prepare onion gratin
Peel the onions (1) and remove the most superficial layers.
Bring a pot full of water to a boil, to which you have added 100 ml of apple cider vinegar; once it reaches a boil, add the onions and cook for 15-20 minutes (2).
When the onions are soft enough, drain them, let them cool under running water and then cut them in half (3).
Line a baking tray with a sheet of parchment paper, place the onions inside and sprinkle with a drizzle of oil (4).
Sprinkle the surface of the onions with little breadcrumbs and grated cheese. Season with a pinch of salt and pepper (5) and bake at 180 ° C for 15-20 minutes.
As soon as the onions are golden brown and crunchy on the surface, take them out of the oven and serve hot (6).
For an optimal result, we recommend blanching the onions in water acidulated with apple cider vinegar: in addition to making them tender and tasty, they will also be much more digestible. It will also cook faster, making it a perfect side dish for a last-minute dinner.
To taste, once you have baked your onion gratin, you can sprinkle everything with plenty of chopped parsley. You can also garnish the preparation with some fried basil leaves.
You can replace the Parmesan with grated pecorino, for a stronger flavour; alternatively, you can arrange a dried tomato and a few cubes of mozzarella on the surface of the onions, then cook as indicated in the recipe.
If you liked this recipe, also try the baked onions and those stewed in a pan.
Keep the onion gratin in the refrigerator for up to 24 hours, in a special airtight food container.