Cut the chuck roast into 3-inch cubes.

Heat a crockpot (if it has a sear function) or a large skillet over medium-high heat. Add a little olive oil and sear each side of the beef for 1-2 minutes until browned. Season with salt and pepper.

If using a skillet, transfer the beef to the crockpot.

In a blender, combine the chopped onion, tomatoes, chipotles with their sauce, water, garlic powder, and salt. Blend until smooth.

Pour the birria sauce over the beef in the crockpot. Cover and cook on low for 8 hours (or high for 4 hours) until the beef is tender and shreds easily with two forks.

Once the beef is done, preheat the oven to 400 degrees.

Transfer the beef to a cutting board, shred it, and place it in a bowl. Stir in 1 cup of the birria sauce from the crockpot.

Spread 1 cup of birria sauce in the bottom of a 9x13-inch baking dish and 1/2 cup in an 8x8-inch baking dish.

Dip a tortilla into the birria sauce in the crockpot, coating both sides. Place it on a plate or cutting board.

Fill with 1/3 cup of shredded beef and 1/2 cup of shredded cheese, then roll up tightly. Place seam side down in the baking dish. Repeat with the remaining tortillas.

Pour the remaining birria sauce from the crockpot over the enchiladas and sprinkle with the remaining cheese.

Bake for 20 minutes, until the cheese is melted and bubbly and slightly golden on top.