Tuna is rich in omega-3 fatty acids, which help prevent and manage heart disease. The sauce on these tasty tuna steaks comes together quickly thanks to sweet fire-roasted tomatoes and salty olives. If you don't regularly purchase olives, stop by your supermarket's olive bar to pick up the exact amount you need.

* 1/4 cup olive oil

* 1 medium yellow onion, thinly sliced

* 1 (14.5-ounce) can no-salt-added fire-roasted diced tomatoes

* 12 pitted green olives, such as picholine

* 12 pitted black olives, such as Kalamata or oil-cured

* 1 tablespoon fresh thyme leaves

* 4 (6-ounce) tuna steaks

* Kosher salt

* Freshly ground black pepper

1. Preheat the grill to medium-high.

2. Heat olive oil in a large skillet over medium. Add onion, and cook, stirring occasionally, 5 to 7 minutes or until tender and lightly browned. Add tomatoes and olives, and cook, stirring, 3 to4 minutes or until mixture is well blended and tomato juice has reduced slightly. Remove from heat, and stir in thyme.

3. Sprinkle tuna steaks with salt and pepper. Grill on greased grill racks 2 minutes on each side or until desired degree of doneness. Transfer tuna steaks to individual plates, and top evenly with tomato-olive mixture.

SERVING SIZE: 1 steak with approx. 1/2 cup sauce; CALORIES: 461; FAT: 28g (sat 5g, unsat 19g); PROTEIN: 41g; CARB: 9g; FIBER: 2g; SUGARS: 4g (added sugars 0g); SODIUM: 616mg; CALC: 6% DV; POTASSIUM: 10% DV