Cook rice according to package directions. Meanwhile, sprinkle the chicken with curry, salt and pepper. In a large skillet, saute chicken and onion in oil until chicken is no longer pink.
Stir in coconut milk and tomato paste. Bring to a boil. Reduce heat; simmer, uncovered, for 5 minutes or until thickened. Add spinach and tomato; cook 2-3 minutes longer or until spinach is wilted. Serve with rice.