Remove the stems and seeds from all of the dried ancho and guajillo chiles, then add ½ cup beef stock to a medium pot and bring to a boil.

Add the chiles, turn off the heat, cover, and let them sit for 15-20 minutes.

Once softened, add them to a blender with the remaining ingredients, and blend until smooth.

Preheat the oven to 350 degrees Fahrenheit.

In a dutch oven over medium-high heat, add the olive oil, then add the chopped beef. Sear on each side with salt, black pepper, and garlic powder for 3-4 minutes until golden. Remove and set aside.

In the same pot, sauté the onions until fragrant and translucent, about 1-2 minutes, then add the chili paste and simmer for another minute.

Add the beef stock and water, stir to combine, then add the seared beef.

Reduce the heat to low and simmer for about a minute.

Transfer the dutch oven to the oven and braise for about 2 ½ hours or until the beef is tender.

Remove from the oven and shred the meat.

Remove 1 cup of the broth, add chopped cilantro to it, and set aside as dipping sauce.

In a skillet, heat olive oil and dip a tortilla in the dipping sauce, fry briefly, and fill with shredded beef, onions, cilantro, and cheese.

Flip to char lightly and repeat until all tacos are made.

Serve with the dipping sauce, Pico de Gallo, or preferred toppings.