1. In a 12-inch frying pan or 5- to 6-quart pan over high heat, combine lemon peel, orange peel, orange juice, chili flakes, and marinara sauce. Stir often until boiling.
2. Add shrimp and stir often until shrimp are opaque but moist-looking in the center of the thickest part (cut to test), 5 to 8 minutes. Add basil and ladle into wide bowls.