Pat the chicken breasts dry with paper towels. Season both sides with 1/4 teaspoon salt, 1/8 teaspoon black pepper, garlic powder, and dried Italian seasoning.
Heat 1 tablespoon olive oil in a large skillet over medium-high heat until shimmering.
Add the chicken breasts to the skillet and cook for 6-7 minutes on one side without moving them.
Flip the chicken breasts and cook for another 6-7 minutes, or until the internal temperature reaches 165°F (74°C) and the chicken is cooked through.
Remove the chicken from the skillet and cover loosely with foil to keep warm.
In the same skillet, reduce heat to medium and add 1 tablespoon olive oil and 1 tablespoon unsalted butter.
Add the minced garlic and sauté for 30 seconds until fragrant.
Add the sliced zucchini, season with the remaining 1/4 teaspoon salt and 1/8 teaspoon black pepper, and sauté for 5-7 minutes, stirring occasionally, until zucchini is tender and lightly browned.
Return the chicken to the skillet for 1 minute to reheat if needed.
Sprinkle chopped fresh parsley over the chicken and zucchini before serving.