Tuna Melt Stuffed Peppers (High-Protein Dinner)

The tuna melt is one of those diner classics that is hard to improve on — creamy, tangy tuna salad under a blanket of melted cheddar. This version keeps everything you love about it and drops the bread: the tuna salad goes straight into sweet roasted bell pepper halves, which act as the perfect edible bowl.

Roasting the peppers first is the key move. Ten to fifteen minutes in a hot oven softens them just enough so they're tender but still hold their shape, and the natural sweetness of the pepper pairs beautifully with the savory, tangy filling. A mix of Greek yogurt and a little mayonnaise keeps the tuna salad creamy while boosting the protein count even further.

With an estimated 32 grams of protein per serving, no bread, and a 35-minute total time, these stuffed peppers work as a light dinner, a meal-prep lunch, or a post-workout plate that actually keeps you full.

Why You'll Love This Recipe

• An estimated 32g of protein per serving — tuna, Greek yogurt, and cheddar do the heavy lifting
• Low-carb and gluten-free — all the comfort of a tuna melt, none of the bread
• On the table in 35 minutes — minimal prep, one sheet pan
• Pantry-friendly — canned tuna and fridge staples you probably already have
• Meal-prep approved — reheats well and the peppers hold up for days

Ingredients

• 4 large bell peppers (any color; red and yellow look best), halved lengthwise and seeded — about 2 1/4 lb / 1 kg
• 1 tablespoon olive oil
• 3 cans (5 oz / 142 g each) tuna in water, drained and flaked
• 1/3 cup plain Greek yogurt (2% or full-fat)
• 2 tablespoons light mayonnaise
• 1 tablespoon Dijon mustard
• 1 celery stalk, finely diced
• 1/4 cup finely diced red onion (about 1/2 small onion)
• 1 teaspoon fresh lemon juice
• 1/2 teaspoon garlic powder
• 1/2 teaspoon fine sea salt, plus a pinch for the peppers
• 1/4 teaspoon freshly ground black pepper
• 1 1/2 cups shredded sharp cheddar cheese (6 oz / 170 g)
• 2 green onions, thinly sliced, for garnish

Save

Instructions

1. Preheat the oven to 400°F (200°C). Line a rimmed baking sheet with parchment paper.
2. Arrange the bell pepper halves cut-side up on the sheet. Drizzle with the olive oil and sprinkle with a pinch of salt. Bake for 12–15 minutes, until just tender but still sturdy enough to hold the filling.
   Save
3. While the peppers bake, make the tuna salad: combine the drained tuna, Greek yogurt, mayonnaise, Dijon mustard, celery, red onion, lemon juice, garlic powder, salt, and black pepper in a medium bowl. Stir with a fork until creamy and well mixed.
4. Remove the peppers from the oven and divide the tuna mixture evenly among the halves, mounding it slightly.
   Save
5. Sprinkle the shredded cheddar evenly over each stuffed pepper, pressing it gently so it sticks to the filling.
   Save
6. Return the sheet to the oven and bake for 6–8 minutes, until the cheese is fully melted and bubbly. For extra-golden spots, broil for 1–2 minutes at the end, watching closely.
7. Let cool for 2–3 minutes, then scatter the sliced green onions over the top and serve warm.

Tips for Success

• Drain the tuna thoroughly. Press it in a fine-mesh strainer or squeeze it with a fork in the can. Excess water makes the filling loose and the peppers soggy.
• Pre-bake the peppers before filling. Raw peppers release water as they cook and never fully tenderize under the filling. The 12–15 minute head start fixes both problems.
• Choose wide, flat-bottomed peppers. Peppers that sit level won't tip over and spill the filling. If one wobbles, trim a thin slice off the bottom so it sits flat.
• Shred your own cheddar. Pre-shredded cheese is coated with anti-caking starch and melts into a drier, grainier layer. A block of sharp cheddar shredded by hand melts silky-smooth.
• Watch the broiler like a hawk. Cheese goes from golden to burnt in under a minute under the broiler. Keep the oven door cracked and your eyes on the pan.
• Taste the filling before you fill. Canned tuna varies in saltiness, so taste the tuna salad and adjust the salt and lemon before spooning it into the peppers.

Variations

• Spicy tuna melt: stir 1 tablespoon of your favorite hot sauce or 1/2 teaspoon red pepper flakes into the tuna salad.
• Dill pickle crunch: swap the celery for 1/4 cup finely chopped dill pickles for extra tang.
• Buffalo style: replace the Dijon with 2 tablespoons buffalo sauce and top with crumbled blue cheese instead of cheddar.
• Mediterranean: use feta in place of half the cheddar, add 1/4 cup chopped Kalamata olives and a pinch of oregano.
• Air fryer version: cook the pepper halves at 375°F (190°C) for 8 minutes, fill and top with cheese, then air fry 3–4 more minutes until bubbly.
• Chicken swap: replace the tuna with 2 cups shredded rotisserie chicken for a chicken-melt version.

Storage

Store leftover stuffed peppers in an airtight container in the refrigerator for up to 3 days. Reheat in a 350°F (175°C) oven for 10–12 minutes until warmed through and the cheese re-melts — the microwave works in a pinch but softens the peppers. The tuna salad filling on its own keeps for 3 days refrigerated and can be stuffed into fresh-baked peppers. This recipe does not freeze well; the peppers turn mushy when thawed.

FAQ

Can I make tuna melt stuffed peppers ahead of time? Yes — bake the peppers and mix the tuna salad up to a day ahead, storing them separately in the fridge. Fill, top with cheese, and bake when ready to serve, adding 2–3 extra minutes to the final bake since the peppers will be cold.

What color bell peppers work best? Any color works, but red, orange, and yellow peppers are sweeter and pair best with the tangy tuna salad. Green peppers are firmer and slightly bitter — fine if that's what you have, but the sweet varieties win here.

Can I use tuna packed in oil? You can — drain it very well and skip the olive oil on the peppers or reduce the mayonnaise slightly, since oil-packed tuna is richer. Tuna in water keeps the filling lighter and the estimated protein count high.

How do I keep the peppers from getting soggy? Pre-baking is the main defense, and draining the tuna thoroughly is the second. Baking on a parchment-lined sheet (not in a deep dish that traps steam) also keeps them firmer.

Is this recipe keto-friendly? With bell peppers as the only real carb source and no bread or crumbs anywhere, these come in around 8g net carbs per serving — they fit comfortably into most low-carb and keto plans.

Recipe Card

• Prep time: 15 minutes
• Cook time: 20 minutes
• Total time: 35 minutes
• Servings: 4 (2 stuffed halves each)
• Estimated calories per serving: ~320
• Estimated protein per serving: ~32g

Save

You May Also Like

• Cheesy Hash Brown Casserole
• Baked Turkey Meatballs
• Creamy Garlic Mushroom Chicken Thighs

Emma Carter

Hi, I’m Emma! I’m the cook and recipe developer behind Sizzle & Sage. From my sunny home kitchen, I share easy, flavor-packed recipes for real life — quick breakfasts, cozy weeknight dinners, and simple bakes anyone can make. Pull up a chair and stay a while!