Preheat your oven to 375°F (190°C).
In a skillet, sauté onions, red bell pepper, and garlic in butter.
Add chopped shrimp, salt, and chili powder; cook until just pink. Stir in lime juice and cilantro.
In a saucepan, melt butter, whisk in flour, then gradually add broth to form a thick sauce.
Stir in salsa verde and cheese until melted, then fold in sour cream off heat.
Fill tortillas with shrimp mixture, roll them up, and place seam-side down in a baking dish.
Pour creamy sauce over enchiladas and top with extra cheese if desired.
Bake for 20–25 minutes or until bubbly and golden. Serve warm!