Heat a large dry skillet over medium heat. Toast the dried chiles for 2-3 minutes per side until fragrant. Transfer to a bowl and cover with hot water. Let soak for 20 minutes until softened.

Season chuck roast chunks generously with salt and pepper. Heat 2 tablespoons oil in a large Dutch oven over medium-high heat. Brown the beef on all sides, about 8-10 minutes total. Remove and set aside.

Drain the soaked chiles and transfer to a blender along with tomatoes, quartered onion, garlic, cumin, and 2 cups of beef broth. Blend until smooth, about 2 minutes.

Strain the chile mixture through a fine-mesh sieve into the Dutch oven. Cook over medium heat for 10 minutes, stirring frequently, until slightly thickened and darkened.

Return the browned beef to the pot along with remaining beef broth and bay leaf. Bring to a boil, then reduce heat to low, cover, and simmer for 2.5-3 hours until beef is fork-tender and easily shreds.

Remove beef from the cooking liquid and shred with two forks. Strain the cooking liquid and skim fat from the surface. This is your consomm?. Season with salt to taste.

To assemble tacos, dip each tortilla in the warm consomm?, then place on a hot griddle or skillet. Add shredded beef and cheese to one half, fold over, and cook 2-3 minutes per side until crispy and cheese is melted.

Serve immediately with small bowls of warm consomm?, diced onion, cilantro, and lime wedges for garnish and dipping.