Steps
1. In a skillet, heat olive oil over medium heat.
2. Add the diced red onion, bell pepper, and zucchini, sautéing for about 3-4 minutes until softened.
3. Add the ground chicken to the skillet, breaking it apart with a spatula. Season with Italian seasoning, salt, and pepper.
4. Cook the chicken until browned and cooked through, about 6-7 minutes.
5. If using, place a slice of mozzarella on top of the chicken mixture and cover for 1-2 minutes until melted.
6. Slice the focaccia bread and layer the chicken-vegetable mixture on one side. Top with fresh basil leaves before closing.
7. Serve warm and enjoy your delicious Mediterranean chicken focaccia sandwich!