Add the rice, water, salt, lime juice, and cilantro to a medium pot; stir well.
Bring to a boil, then cover, reduce heat to low, and simmer for 14 minutes; set aside and keep covered.
Meanwhile, cut the chicken into bite-sized pieces.
Season with half of taco seasoning.
In a very large skillet, or Dutch oven, heat the olive oil over medium-high heat.
Add the chicken in a single layer and cook for 5 minutes, until golden brown, flipping once halfway through, remove to a plate; set aside.
In the same skillet, increase the heat to high, and add the onions, bell peppers, corn, and remaining taco seasoning: cook, stirring occasionally, until veggies are slightly blackened.
Decrease heat to low, add garlic, and stir until combined and fragrant, about 30 seconds.
Add the drained black beans and tomatoes, rice, and chicken: stir all to combine.
Garnish with extra chopped cilantro and top with diced avocado.
