Chicken Tikka Masala

. Chicken tikka
. Salt and freshly ground pepper
. 2 tablespoons plus 1 teaspoon vegetable oil
. 1/4 cup blanched whole almonds
. 1 large onion, finely chopped
. 2 garlic cloves, minced
. 1 teaspoon minced fresh ginger
. 1 1/2 tablespoons garam masala
. 1 1/2 teaspoons pure chile powder
. 1/2 teaspoon cayenne pepper
. One 35-ounce can peeled tomatoes, finely chopped, juices reserved
. Pinch of sugar
. 1 cup heavy cream

. In a small skillet, heat 1 teaspoon of the oil. Add the almonds and cook over moderate heat, stirring constantly, until golden, about 5 minutes. Transfer the almonds to a plate and let cool completely. In a food processor, pulse the almonds until finely ground.

. In a large enameled cast-iron casserole, heat the remaining 2 tablespoons of oil until shimmering. Add the onion, garlic and ginger and cook over moderate heat, stirring occasionally, until tender and golden, about 8 minutes. Add the garam masala, chile powder and cayenne and cook, stirring, for 1 minute. Add the tomatoes with their juices and the sugar and season with salt and pepper. Cover partially and cook over moderate heat, stirring occasionally, until the sauce is slightly thickened, about 20 minutes. Add the cream and ground almonds and cook over low heat, stirring occasionally, until thickened, about 10 minutes longer. Stir in the chicken; simmer gently for 10 minutes, stirring frequently, and serve.