MAKES: 2 cups

TIME: 30 minutes

A tomato-based sauce from India, quite rich, almost sweet, a little hot, and spicy. The butter roasting of the cumin and mustard seeds used essentially as a garnish is an Indian technique called tarka, sometimes translated as tempering. You can also add some minced garlic or ginger to the mix.

I love using this sauce with Hard-Cooked Eggs, cubes of fried tofu or fresh cheese and green peas or another vegetable. I also like it as a dipping sauce for Flaky Indian-Style Flatbread Stuffed with Potato, or Dosa. The sauce is vegan if you use oil and coconut milk.

4 tablespoons (1/2 stick) butter or 1/4 cup neutral oil, like grapeseed or corn

1 medium onion, chopped

2 cloves garlic, minced

One 1-inch piece ginger, peeled and minced

1 tablespoon minced fresh chile (like jalapeo or Thai), or to taste, or hot red pepper flakes or cayenne to taste

2 teaspoons garam masala or curry powder (to make your own, see Garam Masala or Hot Curry Powder)

1/2 teaspoon chili powder (to make your own, see Chili Powder)

Large pinch sugar

Salt and freshly ground black pepper

2 cups chopped ripe tomato (about 1 pound whole), preferably peeled and seeded (see Preparing Tomatoes), or drained canned tomatoes

1/2 cup cream or coconut milk (to make your own, see Coconut Milk)

1/2 cup chopped fresh cilantro leaves

1 teaspoon cumin seeds

1 teaspoon mustard seeds

Put 3 tablespoons of the butter or oil in a deep skillet over medium-high heat. When the butter is melted or the oil is hot, add the onion, garlic, ginger, and chile. Cook, stirring occasionally, until the onion is soft, about 5 minutes. Stir in the garam masala, chili powder, and sugar and sprinkle with salt and pepper; cook and stir until the spices become fragrant, a minute or two more.

Add the tomato and cook, stirring frequently, until it starts to release its liquid, about 3 minutes. Add the cream and the cilantro and keep cooking and stirring until the mixture comes to a boil.

Turn the heat down so that the sauce bubbles gently and cook, stirring occasionally, until the tomato breaks up and the mixture comes together and thickens, about 30 minutes. Taste and adjust the seasoning. (The sauce may be made ahead to this point, cooled, covered, and refrigerated for up to 3 days. Reheat gently before proceeding.)

Put the remaining butter or oil in a small pan over medium-high heat. When the butter is melted or the oil is hot, add the cumin and mustard seeds and toast them until they begin to pop. Spoon over the sauce just before serving.