Machaca (Shredded Beef)

1 (2 pound) beef chuck roast
Water, to cover meat
1/2 onion, sliced
Freshly ground black pepper, to taste
2 tablespoons vegetable oil
1/2 onion, chopped
2 cloves garlic, minced
1 can Ro-Tel tomatoes and green chiles
1 (8 ounce) can tomato sauce
1/2 teaspoon ground cumin
1/2 teaspoon oregano
1/2 teaspoon salt
Flour tortillas

Simmer meat, onion and black pepper in water until very tender, about 2 hours. Drain, and cool until meat is cool enough to handle. Discard bone and fat; shred meat.

Heat oil in large skillet over medium heat. Add onion and garlic; cook until onion is soft, 4-5 minutes.

In a blender, puree Ro-Tel tomatoes (including liquid), tomato sauce, spices and salt. Add to meat. Simmer until meat absorbs most of sauce, 15-20 minutes.

Serve with warm flour tortillas and sour cream, shredded cheese, shredded lettuce, diced tomato and salsa.