Pat the chicken thighs and drumsticks dry with paper towels; season both sides with 3/4 teaspoon kosher salt and 1/2 teaspoon black pepper.
Heat 2 tablespoons coconut oil in a large heavy pot over high heat. Add the chicken thighs skin-side down and sear until golden, about 4–5 minutes; flip and cook 1 more minute. Brown drumsticks on three sides, about 2 minutes per side.
Transfer the browned chicken to a plate and reduce the heat to medium-high.
Add the diced onion and chopped bell pepper to the same pot and sauté about 1 minute until softened.
Stir in the minced garlic, minced ginger, and minced jalapeño; cook 30 seconds until fragrant.
Add 1 tablespoon coriander powder, 1 1/2 teaspoons cumin, 1 1/2 teaspoons turmeric, and 3/4 teaspoon chili powder; cook and stir 30 seconds to bloom the spices.
Pour in the 14-ounce can of full-fat coconut milk and the 14-ounce can of crushed tomatoes, then add 1 teaspoon kosher salt. Stir to combine.
Return the chicken to the pot, submerging pieces mostly in the sauce. Bring to a simmer, cover, and cook over low to medium-low heat for 30 minutes.
Uncover and simmer an additional 10–15 minutes, stirring occasionally, until the sauce thickens and the chicken is cooked through.
Stir in 2 tablespoons lemon juice and 1/2 cup chopped fresh cilantro. Serve the curry over cooked basmati rice.
