Air-fryer roasted tomatoes and onions make a simple, flavorful side or topping for bowls and salads. Roasting concentrates the natural sweetness of the tomatoes and mellows the onions, and using an air fryer speeds the process while delivering caramelized edges and tender interiors. This recipe is easy to adapt with different herbs, spices, or extra vegetables.
Roasted vegetables bring out so much flavor, and the air fryer is a fast, efficient way to get those delicious caramelized notes without heating the whole oven. These tomatoes and onions turn slightly charred at the edges and soft inside—perfect for serving alongside proteins or mixing into grains.
Serve them as a simple side, toss them into grain bowls or salads, or finish with fresh herbs and a sprinkle of feta or freshly grated Parmesan for a touch of richness.
Ingredients
- 2 roma or campari tomatoes (or cherry/grape tomatoes)
- ½ red onion
- 1 tablespoon olive oil
- ½ teaspoon dried oregano or Italian seasoning
- ¼ teaspoon salt
- Red pepper flakes (optional)
- Fresh herbs for serving (parsley, basil, or oregano)
How to customize
This recipe is very flexible.
Switch the herbs—Use thyme, parsley, or tarragon instead of oregano or Italian seasoning.
Add heat—Red pepper flakes are an easy option, or try harissa or calabrian chili paste for a bolder kick.
Mix in other vegetables—Add sliced zucchini, bell peppers, or mushrooms for a larger roasted vegetable medley.
Use different tomatoes—If you only have cherry or grape tomatoes, they work well roasted whole or halved.
What to serve with the tomatoes and onions
These air-fried tomatoes and onions pair well with grilled or air-fried proteins and make a great complement to Mediterranean-style dishes. Try them with chicken cutlets, panko-breaded cod, Mediterranean salmon, or pesto salmon. They also pair nicely with roasted potatoes, leeks, corn on the cob, or garlic bread.
Recipe notes
- Air fryer models vary. Check early and adjust cooking time so the vegetables reach your desired doneness.
- Air fryer parchment paper makes cleanup easier and helps when scooping the finished vegetables, but it is optional.
How to make air-fryer tomatoes and onions
1. Prepare the vegetables: slice the red onion in half, remove the skin, and dice into roughly 1-inch pieces while keeping the layers intact. Dice the tomatoes into 1-inch pieces (or halve cherry/grape tomatoes).
2. Season: place the diced tomatoes and onions in a large bowl. Add the olive oil, dried oregano (or Italian seasoning), salt, and a pinch of red pepper flakes if using. Stir gently to coat; a little separation of the onion layers is fine.
3. Air-fry: transfer the seasoned vegetables to the air-fryer basket in a single layer if possible. Cook at 400°F (200°C) for about 12 minutes, tossing once halfway through so the pieces brown evenly.
4. Finish and serve: when the tomatoes and onions are tender and lightly caramelized, remove them from the air fryer. Plate and garnish with fresh herbs and grated cheese if desired.
Basic recipe card
- Prep time: 5 mins
- Cook time: 12 mins
- Total time: 17 mins
- Servings: 2
- Calories (estimate): 85 kcal per serving
Ingredients (serves 2)
- 2 roma tomatoes
- ½ red onion
- 1 tablespoon olive oil
- ½ teaspoon dried oregano (or Italian seasoning)
- ¼ teaspoon salt
- Red pepper flakes, optional
Instructions
- Dice the tomatoes and red onion into approximately 1-inch pieces.
- Toss tomatoes and onions with olive oil, oregano, salt, and red pepper flakes if using.
- Place in the air-fryer basket and cook at 400°F for 12 minutes, shaking or tossing halfway through.
- Transfer to a plate and top with fresh herbs or cheese if desired.
Notes
- It’s normal for onion layers to separate slightly when tossed with oil and seasonings.
- Adjust the cooking time based on your air fryer model and how caramelized you like the vegetables.
- Using parchment made for air fryers can make cleanup and serving easier, but it is optional.
More healthy air-fryer recipe ideas
- Air-fryer broccolini
- Roasted radishes in the air fryer
- Stuffed tomatoes prepared in an air fryer
- Air-fryer frozen edamame
- Grape or cherry tomatoes air-fried whole
- Sesame green beans
- Lemon asparagus
