Combine rice and water and lemon juice in a saucepan or large skillet with lid. Bring to a boil uncovered. Cover with a lid and turn burner down to a simmer for 15-20 minutes, or until rice is done.
2 cups brown rice, 4 cups water
Meanwhile, cook chicken thighs in a skillet on medium heat, adding taco seasoning to taste. Remove skillet from heat and dice chicken.
3 chicken thighs, 1 tablespoon taco seasoning
Add cooked rice, diced tomatoes, chopped cilantro, lemon juice, and black beans to skillet with chicken.
2 cups black beans, 1-2 tomatoes, 2 cups cilantro, 1 tablespoon lemon juice
Add a large spoonful of rice mixture to a tortilla, sprinkle with cheese, salsa, and lettuce (if desired), wrap up, and enjoy!