Place oven grating on the top most level. Set oven to broil.
Brush cast iron grill pan with vegetable oil. Then place cherry tomatoes in the pan, cut side facing up. Brush tomatoes with vegetable oil.
Sprinkle dried thyme, minced garlic, kosher salt, freshly ground pepper over the tomatoes
Broil (grill) tomatoes for 8 to 10 minutes. Remove from oven.
Transfer to a serving dish. Drizzle balsamic vinegar and extra virgin olive oil over roasted tomatoes. Sprinkle with chopped mint leaves and serve immediately.