Heat the oil in a Dutch oven over medium-high heat. Add tea, and stir-fry about 30 seconds or until fragrant. Add chile pepper and garlic; stir-fry for 30 seconds. Add spinach; stir-fry 2 minutes. Stir in vinegar, and cook 1 minute or until spinach wilts. Sprinkle with sesame seeds, salt, and black pepper. Serve over rice.