Preheat your grill or Blackstone griddle to medium-high heat.
In a large bowl, combine olive oil, minced garlic, salt, black pepper, and Italian seasoning. Mix well.
Add the chicken thighs to the bowl and coat them thoroughly with the marinade. Let them sit for at least 15 minutes to absorb the flavors.
Place the marinated chicken thighs on the preheated grill or griddle. Cook for about 6-7 minutes on each side, or until the internal temperature reaches 165°F.
During the last minute of cooking, sprinkle the grated Parmesan cheese over the chicken and close the lid to melt the cheese.
Once cooked, remove the chicken from the grill and drizzle with fresh lemon juice. Garnish with chopped parsley before serving.