Remove stems and seeds from dried ancho and guajillo chiles.
Add beef stock to a medium pot and bring to a boil.
Add chiles, turn off heat, cover and let sit for 15-20 minutes.
Blend softened peppers with remaining ingredients until smooth and thick; add more stock or water if needed.
Preheat oven to 350°F.
Heat olive oil in a dutch oven over medium-high heat.
Season beef chunks with salt, black pepper, and garlic powder.
Sear beef on all sides until golden, 3-4 minutes per side.
Remove beef and set aside on paper towel-lined plate.
Sauté onions in the same pot until translucent, 1-2 minutes.
Add chili paste and simmer 1-2 minutes.
Add beef stock and water, stir to combine.
Return seared beef to pot, stir, reduce heat to low and simmer 1 minute.
Transfer pot to oven and braise for 2½ hours until beef is tender and shred easily.
Remove from oven and shred beef thoroughly.
Remove 1 cup of broth from pot; add chopped cilantro and set aside as consomé dipping sauce.
Heat a non-stick skillet over medium heat and lightly oil with a paper towel.
Dip a tortilla into the consomé broth and place in skillet.
Add shredded beef, diced onions, chopped parsley, and shredded cheese on tortilla.
Fold tortilla in half and cook until cheese melts and outer side develops a slight char.
Flip and cook until both sides are golden and crispy.
Remove from heat and repeat with remaining tortillas and ingredients.
Serve tacos with consomé dipping sauce and Pico de Gallo.