Name: Grilled Veggie and Mozzarella Sandwich
Prep time: 10 min
Cook time: 15 min
Total time: 25 min
Ingredients: 1 medium zucchini, sliced lengthwise into ½-inch pieces (sub: yellow squash); 1 red bell pepper, seeded and cut into strips; ½ red onion sliced into thin rings; 8 oz portobello mushrooms, stems removed and sliced; 4 ciabatta rolls, split (Can swap for focaccia or sourdough); 8 oz fresh mozzarella, sliced (Use vegan mozzarella for dairy-free option); 3 tbsp extra-virgin olive oil (divided); 2 tbsp balsamic vinegar; 1 tsp honey or maple syrup (Maple for vegan option); 1 clove garlic, minced; ½ tsp sea salt; ¼ tsp freshly ground black pepper; 2 tbsp fresh basil leaves, torn

I first made this grilled veggie and mozzarella sandwich on a sultry Saturday when the farmers’ market was overflowing with bell peppers and baby zucchini. It’s one of those sandwiches that tastes like summer: smoky char on the vegetables, creamy melted mozzarella, bright basil, and a balsamic glaze that ties everything together. If you want a quick, meatless weeknight dinner or a crowd-pleasing picnic option, this sandwich delivers big flavor with minimal fuss — and it pairs nicely with heartier sandwich ideas like a chicken Caesar croissant sandwich if someone at the table wants meat.

Why you’ll love this dish

This sandwich is simple, scalable, and seasonal. It turns cheap summer produce into a satisfying meal in under 30 minutes. The balsamic-honey glaze caramelizes the veggies on the grill, giving you sweet-tangy bites that contrast perfectly with silky fresh mozzarella. It’s also easy to customize for picky eaters or to stretch into a vegetarian main for a weeknight crowd.

"Bright, smoky, and comforting — a go-to for busy nights when you want something special without lots of work."

It’s perfect for:

Weeknight dinners when you want something fast and fresh.
Brunches or light lunches that need a flavorful centerpiece.
Entertaining outdoors — everyone loves assembling their own sandwich.

If you like robust, layered sandwiches, try pairing ideas inspired by other crowd-pleasers such as a chicken torta sandwich for variety.

Step-by-step overview

This recipe is a short, logical sequence:

Prep and slice all vegetables.
Whisk the balsamic glaze and divide it.
Marinate vegetables briefly, then grill until lightly charred.
Grill the ciabatta and melt mozzarella on the bread.
Assemble with basil and a final glaze drizzle, press briefly, and serve.

Expect about 25–30 minutes from start to finish, with most of the time hands-off while the grill does its work.

What you’ll need

4 ciabatta rolls, split
8 oz fresh mozzarella, sliced
1 medium zucchini, sliced lengthwise into ½-inch pieces (sub: yellow squash)
1 red bell pepper, seeded and cut into strips
½ red onion, sliced into thin rings
8 oz portobello mushrooms, stems removed and sliced
3 tbsp extra-virgin olive oil (divided)
2 tbsp balsamic vinegar
1 tsp honey or maple syrup (maple for vegan)
1 clove garlic, minced
½ tsp sea salt
¼ tsp freshly ground black pepper
2 tbsp fresh basil leaves, torn

Notes: Swap ciabatta for focaccia or sourdough if you prefer a different crumb. Use vegan mozzarella and maple syrup to make a dairy-free option.

Directions to follow

Wash and dry all vegetables. Slice the zucchini into ½-inch lengthwise pieces. Cut the red pepper into strips. Cut the red onion into thin rings. Slice the portobello mushrooms. Put everything into a large bowl.
In a small bowl, whisk 2 tbsp olive oil, the balsamic vinegar, honey or maple syrup, minced garlic, sea salt, and black pepper until combined.
Pour half the glaze over the vegetables. Toss until lightly coated. Let them rest for 5 minutes while the grill heats.
Preheat the grill to medium-high (around 400°F). Oil the grates or the grill pan lightly to prevent sticking.
Grill the marinated vegetables 3–4 minutes per side. You want tender-crisp pieces with nice char marks — don’t overcook. Remove to a plate.
Brush the cut sides of the ciabatta with the remaining glaze. Grill the bread cut-side down 1–2 minutes until lightly crisp.
While the bread is still on the grill, place mozzarella slices on the bottom halves. Cover with a lid or a metal bowl for 30–45 seconds to melt the cheese slightly.
Pile the grilled vegetables on top of the melted mozzarella. Drizzle any remaining glaze and scatter torn basil leaves.
Close the sandwich, press gently, and give it a final 1-minute press on the grill to warm through.
Remove, let rest for a minute, then slice and serve warm.

Keep gestures short and intentional when grilling — quick flips preserve texture and char.

Best ways to enjoy it

Serve the sandwich while the mozzarella is still warm and slightly melted. Good side ideas:

A crisp green salad with lemon vinaigrette.
Oven-roasted potato wedges or sweet potato fries.
A light tomato-basil soup for dipping.

For an easy platter at a casual gathering, serve stacked sandwiches with a bowl of extra balsamic glaze for dipping, and offer pickles or a pepperoncini bowl on the side. If you want a richer meal, pair with a warm, beefy sandwich like crockpot French dip sandwiches on the side for meat-lovers.

Storage and reheating tips

Refrigerator: Store leftover components separately if possible (bread, veggies, cheese). Refrigerate in airtight containers for up to 3 days. Mixed assembled sandwiches hold for about 24 hours before bread gets soggy.
Reheating: Reheat in a skillet over medium-low heat or in an oven at 350°F for 8–10 minutes to revive the crust and melt the cheese. Avoid microwaving — it makes the bread chewy.
Freezing: I don’t recommend freezing assembled sandwiches (mozzarella and grilled veggies release water). You can freeze grilled vegetables in a sealed container for up to 2 months; thaw in the fridge and reheat on the grill or skillet.
Food safety: Keep perishable ingredients below 40°F if not eating immediately. Discard any sandwich left out >2 hours (1 hour if above 90°F).

Pro chef tips

Dry vegetables thoroughly before glazing. Excess moisture steams the veggies instead of charring them.
Cut vegetables uniformly for even cooking. Half-inch zucchini slices and similar-thickness pepper strips work best.
Use fresh mozzarella that’s well-drained. Pat slices dry to prevent watery sandwiches.
For extra flavor, reserve a few basil leaves and add them after grilling rather than cooking them — fresh basil loses its brightness when heated too long.
If you don’t have a grill, a heavy cast-iron pan or grill pan works well; preheat until smoking hot to get those char marks.
To make it vegan: replace mozzarella with a firm vegan melting cheese and swap honey for maple syrup. For more cheesy-bread inspiration, I like recipes that layer tomato and cheese like this slow-cooker chicken with marinara and mozzarella (swap the protein for roasted vegetables).

Creative twists

Add pesto: spread basil pesto on the bread before adding mozzarella for a herby punch.
Spicy kick: toss sliced jalapeños with the veggies or brush a cayenne-spiked olive oil on the bread.
Grainy crunch: add thinly sliced roasted eggplant or a smear of olive tapenade for depth.
Protein boost: add thinly sliced grilled halloumi, marinated tofu, or leftover grilled chicken if desired.
Open-face salad: serve the grilled veggies over a single slice of toasted ciabatta with torn mozzarella and a heavy drizzle of glaze.

Your questions answered

Q: How long does the whole recipe take?
A: Plan on 25–30 minutes total: 5–10 minutes prep and about 10–15 minutes grilling/assembly.

Q: Can I make the glaze ahead?
A: Yes — the balsamic-honey glaze keeps in the fridge for up to a week. Bring to room temperature and whisk before using.

Q: Will this work on an indoor grill pan?
A: Absolutely. Use high heat and a lightly oiled pan. Work in batches to avoid overcrowding and steaming the vegetables.

Q: How do I keep the bread from getting soggy?
A: Grill the bread cut-side down until crisp and try to assemble right before serving. You can also spread a thin layer of mayo or pesto on the bread to act as a moisture barrier.

Q: Can I make this gluten-free?
A: Yes — swap ciabatta for a gluten-free roll or sturdy gluten-free bread and grill gently to avoid falling apart.

Conclusion

If you want more grilled-vegetable sandwich inspiration, this version focuses on simplicity and bright contrasts between smoky veg and fresh mozzarella. For alternate flavor profiles and pesto-forward recipes, check out this Grilled Vegetable Mozzarella Pesto Sandwich – The Table Of Spice and also this take on a pesto-and-mozzarella grilled veggie sandwich from Grilled Vegetable Sandwich with Pesto and Mozzarella – The Lemon Bowl.