01 - Combine rice, 2 cups water, and 1/2 teaspoon salt in a medium saucepan. Bring to a boil over high heat, then reduce to low, cover, and simmer for 15 minutes until liquid is absorbed. Remove from heat and let stand covered for 5 minutes. Fluff with a fork and stir in cilantro and lime juice if desired.
02 - Heat olive oil in a large skillet over medium heat. Add chopped onion and sauté for 2-3 minutes until softened. Add minced garlic and cook 30 seconds until fragrant. Add ground beef, breaking apart with a spoon, and cook until browned, approximately 5-6 minutes. Drain excess fat if necessary.
03 - Add chili powder, cumin, smoked paprika, oregano, salt, and pepper to the browned beef. Stir in tomato sauce and beef broth. Reduce heat to low and simmer for 5 minutes until sauce slightly thickens, stirring occasionally.
04 - Combine drained black beans, cumin, chili powder, salt, and 1/4 cup water in a small saucepan over medium heat. Cook for 3-4 minutes, stirring occasionally, until heated through and slightly thickened.
05 - Wrap tortillas in aluminum foil and warm in a 350°F oven for 5 minutes. Alternatively, microwave stacked tortillas wrapped in a damp paper towel for 30 seconds until pliable.
06 - Place a warmed tortilla on a flat surface. Spoon portions of rice, seasoned beans, and beef mixture in the center. Top with shredded cheese, salsa, lettuce, and sour cream. Fold both sides inward toward the center, then roll from bottom to top, tucking ingredients tightly as you roll.