Prepare your shrimp by peeling and deveining them; if using frozen, thaw and pat them dry. Thinly slice the yellow onion and, if desired, seed and dice the jalapeños. Finally, dice the vine tomatoes.

In a large skillet, heat 1-2 tablespoons of vegetable oil over medium heat. Add the sliced onion and diced jalapeños (if using), sautéing for 5-7 minutes until tender. Stir in the minced garlic and cook for an additional minute, then add the diced tomatoes, cooking for 2-3 minutes until softened.

Pour in 1½ cups of heavy whipping cream and ½ cup of sour cream, stirring until well combined. Bring to a gentle simmer over medium-low heat, allowing it to thicken. Stir in ¼ teaspoon of cayenne pepper, ½ teaspoon of chipotle chili powder, and ½ teaspoon of ground cumin, seasoning with salt to taste. Simmer for 5-10 minutes until creamy.

Add the peeled shrimp to the sauce, cooking for 3-5 minutes until they turn pink and opaque. Remove from heat to prevent overcooking.

Warm the flour tortillas in a dry skillet over low heat until pliable. Spoon a portion of the shrimp and sauce onto one half of each tortilla, then sprinkle with 8 ounces of freshly grated Monterey Jack cheese. Carefully fold the tortilla in half.

Preheat your oven to 375°F (190°C). Lightly grease a baking dish. Place the folded enchiladas seam-side down in the dish, covering with any remaining sauce and the remaining cheese.

Bake the enchiladas for 15-20 minutes until the cheese is melted and bubbly, allowing them to rest for a few minutes before serving.