Grilled tuna, red onion, and roasted pepper sandwiches

Total Time
33 min
15 min
18 min
Upgrade your sandwich with fresh yellowfin tuna simply seasoned with olive oil, salt and pepper and topped with tender grilled onions and sweet red bell pepper. Basil and lemon zest mixed into mayonnaise makes a tangy spread for this flavorful sandwich. You may prefer to toast the sourdough bread or throw it on the grill with the tuna. When purchasing tuna, look for moist and shiny fish, which is an indication of freshness. If purchasing prepackaged arugula, select a bag without excess water which can cause the arugula to rot more quickly. Serve this sandwich for lunch or dinner with a bowl of chilled gazpacho or a crisp cucumber-dill salad.


Reduced calorie mayonnaise

2 Tbsp


2 Tbsp, fresh, chopped

Lemon zest

2 tsp, grated

Uncooked red onion(s)

1 medium, cut into 4 thick slices

Sweet red pepper(s)

1 medium, seeded and quartered

Olive oil

1 Tbsp, exra-virgin

Table salt

¾ tsp

Black pepper

¼ tsp, freshly ground

Uncooked yellowfin tuna

24 oz, steak, or other tuna variety, 4 (6-ounce and 1⁄2 inch thick)

Sourdough bread

8 slice(s), medium, about 3 x 5 inches


1 cup(s), loosely packed leaves


  1. Combine the mayonnaise, basil, and lemon zest in a small bowl; set aside.
  2. Spray the grill rack with nonstick spray; prepare the grill.
  3. Brush the onion slices and bell pepper pieces with 1 teaspoon of the oil, then sprinkle evenly with 1⁄2 teaspoon of the salt and 1⁄8 teaspoon of the pepper. Place on the grill rack and cook until the vegetables are well marked and tender, 3–4 minutes on each side. Transfer the vegetables to a plate and set aside.
  4. Brush the tuna with 1 teaspoon of the oil, then sprinkle with the remaining 1⁄4 teaspoon salt and 1⁄8 teaspoon pepper. Place the tuna steaks on the grill and cook until browned on the outside but still a little pink in the center, 3–4 minutes on each side. Transfer the tuna to a plate and set aside.
  5. Place 1⁄4 cup arugula leaves on each of 4 slices of bread; top each with an onion slice, a piece of bell pepper, and a tuna steak. Spread one side of each of the remaining 4 bread slices with the mayonnaise mixture, then place on top of the tuna steaks. Yields 1 sandwich per serving.


We like it cooked medium-rare—still a little pink in the center, but you can leave it on the grill a little longer if you prefer it well-cooked.