Preheat your oven to 400°F (200°C) and grease a spacious 9x13-inch baking dish with olive oil or cooking spray.

In a large skillet, heat 1 tablespoon of olive oil over medium heat. Add chopped onion, diced red bell pepper, and minced jalapeño. Sauté for about 5 minutes until soft and translucent.

Stir in minced garlic and cook for about 1 minute. Then, add raw shrimp and ground cumin. Cook until shrimp turns pink, around 2-3 minutes. Season with salt and pepper.

In the same skillet, melt 3 tablespoons of butter over medium heat. Whisk in 2 tablespoons of all-purpose flour and cook for 1-2 minutes. Gradually add 1 cup of chicken broth, stirring for about 5 minutes until the sauce thickens.

Remove the skillet from heat and mix in 1 cup of sour cream and half of the shredded Monterey Jack cheese.

Spread a thin layer of the creamy sauce on the bottom of the baking dish. Fill warm tortillas with the shrimp mixture, roll tightly, and place seam-side down in the dish.

Pour the remaining creamy sauce over the enchiladas and sprinkle with the remaining cheese.

Bake in the preheated oven for 20-25 minutes until the cheese is melted and bubbly. Let sit before serving, garnished with fresh cilantro.