01 - Rinse the brown rice under cold water. In a saucepan, combine the rice, water, and salt. Bring to a boil, then reduce heat to low, cover, and simmer for 25 minutes until tender and water is absorbed. Fluff with a fork and set aside.
02 - While rice cooks, heat olive oil in a large skillet over medium heat. Add the chopped onion and cook for 2 to 3 minutes until softened. Stir in the minced garlic and cook for 30 seconds.
03 - Add the ground beef to the skillet, breaking it up with a spoon. Cook until browned, approximately 5 to 7 minutes. Drain excess fat if necessary.
04 - Mix in chili powder, ground cumin, smoked paprika, dried oregano, salt, and black pepper. Stir in tomato paste and water. Simmer for 4 to 5 minutes until the mixture thickens. Adjust seasoning to taste.
05 - Dice the avocado, halve the cherry tomatoes, drain the sweetcorn and black beans, and shred the lettuce and cheddar cheese.
06 - Distribute the brown rice into 4 bowls. Top each with the beef mixture. Arrange avocado, cherry tomatoes, sweetcorn, black beans, shredded lettuce, and shredded cheddar cheese on top. Add a dollop of sour cream, a lime wedge, and garnish with fresh cilantro leaves.
07 - Serve the bowls right away, allowing diners to mix their ingredients as desired.