Prepare the beef chuck roast by trimming excess fat.
Season the beef with salt, pepper, cumin, chili powder, and smoked paprika.
Place the seasoned beef in the slow cooker.
Add diced onion, minced garlic, and diced tomatoes on top of the beef.
Cover the slow cooker and cook on low for 8 hours or high for 4 hours.
Once cooked, shred the beef using two forks and mix with the juices.
Warm the tortillas in a pan or microwave.
Assemble the burritos by placing shredded beef and cheese in the center of each tortilla.
Fold in the sides and roll up the tortilla tightly.
Serve warm, garnished with fresh cilantro if desired.
