First, poach the chicken: Put the chicken breasts in a medium-sized pot and cover it with water. Bring to a boil over high heat, then reduce the heat to medium and cook for about 10-13 minutes or until fully cooked.
Shred the chicken: Place one of the chicken breasts on a large plate and, using two forks, start pulling the chicken into pieces; it’s that simple!
Make the taco filling: Heat the olive oil in a large frying pan over medium heat, add the onions and cook for 2 to 3 minutes until softened.
1 tablespoon olive oil, 1 red onion
Add shredded chicken, taco seasoning, beans, and water. Let simmer for 2 to 3 minutes.
Now, divide the chicken mixture between the taco shells, sprinkle cheese on top.
2 tablespoon taco seasoning, 3 chicken breasts, 400 g kidney beans, ½ cup water
Bake in the oven at 180C / 350F for 10-12 minutes or until the cheese is melted.
12 taco shells, 2 cups mozzarella cheese
Top the baked tacos with tomatoes and a tablespoon of mashed avocado. Garnish with cilantro and serve.
1 avocado, 1 large tomato
Notes
I highly recommend shredding the chicken while it's still warm; it's much softer and easier to pull apart.
If you don’t have time to cook the chicken, a store-bought rotisserie chicken is an easy and convenient option.