In a large skillet, heat the olive oil over medium-high heat. Add the diced onion and sauté until translucent, about 5 minutes. Add the minced garlic and cook for an additional minute until fragrant.

In a small bowl, mix together the chili powder, cumin, smoked paprika, salt, and black pepper. Rub this spice mixture all over the beef chuck roast.

Place the seasoned roast in the slow cooker. Top with the sautéed onion and garlic mixture, then pour in the beef broth and red enchilada sauce.

Cover and cook on low for 8 hours or on high for 4 hours, until the beef is tender and easily shredded with a fork.

Once cooked, remove the beef from the slow cooker and shred it with two forks. Return the shredded beef to the slow cooker and mix it with the sauce.

Preheat your oven to 350°F.

To assemble the enchiladas, take a tortilla and fill it with a generous amount of the shredded beef mixture and a sprinkle of cheese. Roll it up tightly and place it seam-side down in a greased 9x13 inch baking dish. Repeat with the remaining tortillas.

Pour any remaining sauce from the slow cooker over the top of the enchiladas and sprinkle with the remaining cheese.

Bake in the preheated oven for 20-25 minutes, until the cheese is melted and bubbly.

Serve hot, topped with sour cream and garnished with fresh cilantro.