Shredded Beef Tostadas

Name: Shredded Beef Tostadas
Ingredients: 2 teaspoons chipotle chili powder, or to taste; 1 teaspoon smoked paprika; 1 teaspoon dried Mexican oregano; 1 teaspoon garlic powder; 1 teaspoon onion powder; 0.5 teaspoon ground coriander; 0.5 teaspoon ground cumin; 0.5 teaspoon salt, or to taste; 0.5 teaspoon ground black pepper, or to taste; 1 (2 pound) boneless beef chuck roast; 1 tablespoon extra-virgin olive oil; 0.5 cup chopped onion; 1.5 teaspoons minced fresh garlic; 1 cup beef stock; 1.5 cups chopped tomatoes, divided; 1 medium orange, juiced; 0.5 medium lime, juiced; 6 crispy tostada shells; 2 cups refried beans, warmed; 2 cups shredded lettuce; 1.5 cups shredded Cheddar cheese; 3 tablespoons salsa, or to taste; 3 tablespoons sour cream, or to taste; 3 tablespoons guacamole, or to taste; 0.25 cup chopped fresh cilantro; 6 wedges lime