01 - Rinse rice under cold water until clear. Combine rice, water, and salt in a saucepan. Bring to a boil, reduce heat to low, cover, and simmer for 15 minutes or until tender. Remove from heat, fluff with a fork, then stir in lime juice and cilantro if desired.
02 - Heat olive oil in a large skillet over medium heat. Add chopped onion and cook 2 to 3 minutes until softened. Add garlic and cook for 30 seconds. Add ground beef, breaking it apart. Cook until browned, about 5 to 7 minutes. Drain excess fat if necessary.
03 - Stir in cumin, smoked paprika, chili powder, oregano, salt, and black pepper. Mix well. Pour in tomato sauce and simmer for 3 to 4 minutes until slightly thickened.
04 - Place black beans in a small saucepan with a splash of water. Heat over low heat until warmed through, about 2 to 3 minutes.
05 - Divide rice evenly among 4 bowls. Top with seasoned beef, black beans, corn, cherry tomatoes, avocado, shredded cheese, and a dollop of sour cream or Greek yogurt.
06 - Finish with fresh cilantro leaves, jalapeño slices if desired, and lime wedges. Serve immediately.