keto chicken recipe

4 boneless, skinless chicken thighs - Salt and black pepper to taste - 2 tablespoons olive oil - 4 cloves garlic, minced - 1/2 cup chicken broth - 1/4 cup heavy cream - 1/4 cup grated Parmesan cheese - 2 tablespoons butter - 1 teaspoon Italian seasoning - 1/2 teaspoon garlic powder - 1/2 teaspoon onion powder - 1 cup baby spinach leaves - Fresh parsley, chopped (for garnish)