A staple in Indian, Thai, and Caribbean cuisines, mild-flavored coconut milk is used to enhance everything from curries to desserts.
In a medium saucepan, cover potatoes with salted water by 1 inch. Bring to a boil; reduce heat, and simmer until potatoes are fork-tender, 10 to 12 minutes. Drain.
Meanwhile, in a bowl, toss chicken with curry powder and 1 teaspoon salt. In a large nonstick skillet, heat 1 teaspoon oil over medium-high heat; cook half the chicken, turning often, until browned and cooked through, 5 to 6 minutes. Transfer to a plate. Repeat with another teaspoon oil and remaining chicken.
Reduce heat to medium-low. Cook garlic and pepper flakes in remaining teaspoon oil until fragrant, about 1 minute. In a small bowl, whisk together coconut milk, tomato paste, and 1/4 cup water. Pour into pan; add peas, and stir until liquid just begins to simmer.
Return chicken to pan along with potatoes; toss until warmed through and coated with sauce, 1 to 2 minutes. Serve topped with peanuts.
After adding the coconut milk, do not let the sauce boil as the milk may separate.