Chicken Curry with Tamarind

Chicken Curry with Tamarind
Serves 4

1/2 cup tamarind pulp (4 ounces)
1 cup boiling water
10 black peppercorns
6 dried red chiles
1 tablespoon coriander seeds
1 teaspoon cumin seeds
One cinnamon stick
2 tablespoons vegetable oil
2.5 lbs chicken thighs, in pieces
Salt and freshly ground pepper
1 large onion, minced
5 garlic cloves, minced
1 1/2 tablespoons minced ginger
1 teaspoon turmeric
2 chiles, minced
1 can coconut milk
10oz chopped spinach

Soak the tamarind pulp in boiling water, covered, until softened, 30 minutes. Strain and discard the seeds.
Add the onion to a dutch oven and cook over moderately low heat, stirring occasionally, until softened, about 6 minutes. Add the garlic, ginger, turmeric, ground spices and green chiles. Cook, stirring, until fragrant, 3 minutes.
Add the chicken and brown a bit.
Stir the strained tamarind water into the casserole. Return the chicken to the casserole and bring to a boil, then simmer over low heat for 20 minutes. Add the coconut milk and simmer for 20 minutes longer. Transfer the remaining chicken to the plate and simmer the sauce until very flavorful, about 8 minutes. Season with salt and pepper.
Add spinach and garnishes, heat through, and serve.