Grilled Tuna with Stir-Fry Vegetables — Quick, Bright, and Healthy

The weather here in Missouri has been unpredictable — warm and sunny one day, chilly and cloudy the next. On a recent sunny day I took advantage of the warmth to fire up the grill and make this simple grilled tuna recipe paired with stir-fried vegetables. It’s a bright, healthy meal that comes together in about 30 minutes and works well for a weeknight dinner or a weekend cookout.

This version has a touch of heat from Sriracha in the marinade, balancing savory and sweet flavors. If you prefer something milder and sweeter, you can reduce or omit the Sriracha, or swap in a little honey. The tuna stays moist when seared quickly on high heat and served rare to medium-rare; overcooking will dry it out, so watch the time carefully.

Why this grilled tuna recipe works

Quick cooking, bold flavor, and fresh vegetables make this dish satisfying without feeling heavy. The stir-fried vegetables add color, crunch, and a variety of textures, while a simple sauce of mirin, soy, fish sauce, sesame oil and brown sugar ties the dish together. The sesame seeds add a toasty finish and a pleasant mouthfeel. This is a healthy seafood dinner option that’s high on flavor and low on fuss.

Ingredients (serves 4)

1 pound sushi-quality yellowfin tuna, cut into four 4 oz pieces
Salt and pepper, to taste
2 tablespoons canola oil (for grilling)
1 tablespoon mirin
1 tablespoon water
1 tablespoon sesame oil
1 teaspoon soy sauce
1 tablespoon fish sauce
1/2 teaspoon Sriracha (adjust to taste)
1 tablespoon sesame seeds
1 tablespoon brown sugar
1 teaspoon sesame oil (for stir-frying)
1 red onion, julienned
1 red bell pepper, cut into 1/4″ strips
6 stalks asparagus, cut on the bias
2 stalks celery, cut into 1/4″ strips
2 cloves garlic, minced
1 head baby bok choy, cut into thin strips
Fresh cilantro for garnish

Preparation and cooking

Prepare the tuna: Heat your grill or grill pan to high. Pat the tuna dry and season lightly with salt and pepper. Brush with about 1 tablespoon of canola oil. Sear the tuna for roughly 1 minute per side for a rare center; increase time slightly if you prefer medium. The key is to get a good sear while keeping the inside moist and slightly pink. Remove from heat and let rest briefly before slicing.

Make the sauce: In a small bowl, whisk together mirin, sesame oil, water, soy sauce, fish sauce, Sriracha, sesame seeds, and brown sugar. Taste and adjust heat or sweetness as desired. Reserve about a tablespoon for stir-frying the vegetables and save the remainder for finishing the tuna.

Stir-fry the vegetables: Heat a wok or large sauté pan over medium-high heat. Add 1 teaspoon sesame oil and wait until it is hot and just starting to shimmer. Add the julienned red onion and stir for about 15 seconds until it begins to brown. Add the bell pepper, asparagus, celery, and garlic and stir for another 30 seconds. Toss in the bok choy and cook for an additional 30 seconds. Add 1 tablespoon of the prepared sauce to the pan, toss briefly to coat, then remove from heat. The vegetables should remain crisp-tender with bright color.

To serve

Spoon a mound of stir-fried vegetables onto each plate. Slice the grilled tuna into 1/4″ thick slices and fan it over the vegetables. Drizzle a little of the reserved sauce over the tuna and finish with a sprig of fresh cilantro. Serve immediately while the tuna is warm and the vegetables are crisp.

Tips, variations and storage

If you prefer less heat, reduce or omit the Sriracha and add a splash of extra mirin or a little honey for sweetness.
Vegetable substitutions: snap peas, snow peas, green beans, or thinly sliced zucchini all work well if you don’t have asparagus or bok choy on hand.
For a gluten-free version, use tamari or a gluten-free soy sauce substitute and confirm your fish sauce is gluten-free.
Leftovers: store tuna and vegetables separately in airtight containers in the refrigerator and eat within 24–48 hours. Cold leftover tuna tastes great in salads or sandwiches; reheat the vegetables briefly in a hot pan if you prefer them warm.

Prep and cooking time combined is about 30 minutes, making this grilled tuna with stir-fry vegetables a reliable, flavorful option when you want a healthy meal without a lot of time in the kitchen. Enjoy!