1. Prepare tuna. Preheat grill. Mix oil, lime juice, cumin, coriander, and peppertogether in a small bowl. Rub mixture all over the tuna steaks, coating them evenly. Set aside.
2. While grill heats, begin salad. In a large bowl, whisk together vinegar, salt, pepper, and oil. Add watermelon, mint, and onion and toss well. Set aside.
3. When grill is very hot, brush with oil or spray with vegetable cooking spray. Grill tuna until well marked, about 5 minutes. Turn to finish cooking, about 3 minutes for rare, 5 minutes for medium rare. Transfer tuna to plate.
4. Add spring mix to watermelon salad and toss well. To serve, divide salad and tuna among 4 plates. Garnish each salad with about 2 Tbsp. crumbled feta.
Source: Hannaford fresh Magazine, July - August 2013