In a large bowl, combine the olive oil, minced garlic, grated Parmesan cheese, oregano, salt, black pepper, red pepper flakes, and lemon juice. Mix well to create a marinade.
Add the chicken cubes to the marinade, ensuring they are well coated. Cover the bowl with plastic wrap and refrigerate for at least 30 minutes, or up to 2 hours for more flavor.
Preheat your grill to medium-high heat. If using wooden skewers, soak them in water for 30 minutes to prevent burning.
Thread the marinated chicken onto the skewers, leaving a little space between each piece for even cooking.
Place the skewers on the grill and cook for 10-12 minutes, turning occasionally, until the chicken is cooked through and has nice grill marks. The internal temperature should reach 165°F.
Remove the skewers from the grill and let them rest for a few minutes. Garnish with chopped fresh parsley before serving.