How to Make It
Light a grill. In a bowl, combine the yogurt with the lemon juice, vinegar, thyme and the 1 tablespoon of olive oil. Season with salt and pepper.
Drizzle the watermelon triangles with olive oil and season with salt and pepper. Grill over high heat until nicely charred, about 1 minute per side; transfer to plates. Top the watermelon with the yogurt sauce and season with black pepper. Drizzle with olive oil, garnish with the mint and serve.