For the Chimichangas:

• 2-pound boneless beef chuck roast, trimmed of fat
• 1 1/2 teaspoons coarse salt, divided, plus more to taste
• 1 1/2 teaspoons freshly ground black pepper, divided 
• 2 tablespoons vegetable oil
• 1 large yellow onion, chopped (about 2 cups)
• 1 canned chipotle pepper in adobo, rough chopped
• 1 4-ounce can diced green chilies
• 2 cups low-sodium or homemade beef stock
• 1 tablespoon ground cumin
• 1 1/2 tablespoons chili powder blend
• 1 tablespoon garlic powder
• 1 teaspoon dried oregano
• 1 dried bay leaf
• 8 burrito-size flour tortillas
• 2 cups shredded sharp cheddar cheese
• Toothpicks
• Vegetable oil, for frying

For Serving:

• 1 cup sour cream
• 1 cup jarred or homemade salsa
• 1/4 cup rough chopped fresh cilantro