Mix all the spices (from the cumin to the turmeric) in a small bowl.
Place chicken in a large bowl and sprinkle the spice mixture over it. Let it sit for 30 minutes.
Heat 1 Tbsp of oil in a large skillet over medium-high heat. Add onion and jalapeño and cook for about 3 minutes. Then add the garlic and cook for one more minute, until fragrant. Remove mixture from skillet and place in a medium size bowl.
Add remaining Tbsp of oil to the same skillet and add half of the chicken pieces, spreading them out to make sure they’re not overcrowded. Cook for a few minutes on each side to cook through and lightly brown. When cooked through, remove from the skillet and add them to the bowl of onion/jalapeño. Repeat with remaining chicken and remove that to the bowl, too.
Pour the coconut milk into the skillet. Cook on medium-high and stir until sauce thickens and starts bubbling a bit. Mix in the Worcestershire sauce.
Add the chicken and onion/jalapeño mixture back into the skillet, along with basil and ginger and cook for 2 more minutes.
Serve basil chicken over rice. Spoon more coconut curry sauce over the top. Top with more basil if desired.