• 4 tablespoons (2 ounces) unsalted butter
  • 1 pound onions, chopped
  • 1 quart Béchamel sauce
  • 2 cups tomato puree, optional


    step 1

    In a heavy-bottomed saucepan, melt the butter over medium heat. Add the onions and cook until they are soft and translucent. Make sure not to let them turn brown.

    step 2

    Transfer the cooked onions to a food processor. Purée briefly and then return them to the pot.

    step 3

    Whisk the béchamel into the puréed onions and bring the sauce to a simmer.

    step 4

    Add the tomato purée, if using, and gently mix over the heat until combined.

    step 5

    Serve right away with roasted meats or vegetables.