Season the chicken breast evenly with sea salt, black pepper, and garlic powder on both sides.
Heat the olive oil in a grill pan or cast-iron skillet over medium-high heat.
Place the chicken in the pan and cook for 6 to 7 minutes per side until the internal temperature reaches 165°F and the surface is golden brown.
While the chicken is cooking, prepare the salsa by dicing the avocado, halving the cherry tomatoes, and finely mincing the red onion.
In a small mixing bowl, combine the avocado, tomatoes, red onion, lime juice, and chopped cilantro.
Gently toss the salsa ingredients together to ensure they are coated in lime juice without mashing the avocado.
Remove the chicken from the heat and let it rest for 3 minutes to lock in the juices.
Slice the chicken if desired and top with the fresh avocado and tomato salsa before serving.