Enchiladas Rojas de Queso (Cheese Enchiladas in Red Sauce)

Toast the guajillo and ancho chiles in a dry skillet over medium heat, 20 seconds per side, until fragrant and slightly puffed, then place in a saucepan, cover with the vegetable broth, and simmer for 10 minutes until fully softened.
Transfer the softened chiles and their broth to a blender along with the roughly chopped onion, garlic, cumin, and 1 teaspoon salt. Blend for 1 minute until completely smooth.
Strain the sauce through a mesh sieve into a bowl, pressing with a spoon to extract the liquid, and discard the tough skins left behind.
Heat the oil in a medium saucepan over medium heat, then carefully pour in the strained sauce. Simmer for 8 minutes, stirring occasionally, until slightly thickened; taste and adjust salt.
Preheat the oven to 375 F and lightly grease a 9x13-inch baking dish.
Warm the corn tortillas one at a time in a dry skillet for 15 seconds per side, just until pliable and soft enough to fold without cracking.
Dip each tortilla in the warm red sauce to coat both sides, then lay it flat and sprinkle 2 tablespoons of shredded cheese and a pinch of finely diced onion down the center.
Roll the tortilla up snugly around the filling and place it seam-side down in the prepared baking dish. Repeat with all 12 tortillas.
Pour any remaining sauce evenly over the rolled enchiladas, then sprinkle the remaining cheese on top.
Bake uncovered for 15 minutes, until the cheese is fully melted and the sauce is bubbling at the edges.
Let the dish rest 5 minutes before serving. Top with a drizzle of crema, diced onion, and chopped cilantro.

Dip the tortillas in the sauce while it is still warm and fluid, not thick and cold, so they coat evenly without tearing.

Do not skip straining the blended sauce; dried chile skins are fibrous and will make the finished sauce grainy instead of silky if you pour it straight from the blender.