1Preheat gas grill to medium-high. Combine olive oil and pepper flakes in small bowl; reserve.
2Combine butter with 2 teaspoons orange zest and 1 teaspoon thyme leaves in small bowl; reserve.
3Place the patties on the grill, cover, and cook, turning once, until cooked through, 6 to 8 minutes per side. During the last 2 minutes of cooking time, top patties with equal portions cheese mixture.