In a large skillet, heat olive oil over medium heat. Sauté the chopped onion until softened, about 3 minutes. Add garlic and cook for another 30 seconds.
Add the shrimp, cumin, paprika, and chili powder. Cook for 2–3 minutes, or until the shrimp turn pink.
Remove from heat and stir in 1 cup of shredded cheese and cilantro (if using).
In a saucepan, melt butter over medium heat. Stir in the flour and cook for about 1 minute, making a roux.
Gradually whisk in the broth and cook until the sauce thickens, about 3–4 minutes.
Remove from heat and stir in sour cream, 1/2 cup of shredded cheese, garlic powder, lime juice, salt, and pepper.
Preheat the oven to 375°F (190°C). Spread 1/2 cup of the creamy sauce on the bottom of a greased baking dish.
Divide the shrimp mixture among the tortillas, roll them up, and place seam-side down in the dish.
Pour the remaining sauce over the enchiladas and sprinkle with the remaining cheese.
Bake uncovered for 20–25 minutes, or until the cheese is melted and bubbly.
Garnish with fresh cilantro, lime wedges, and serve with rice or salad.