Skip to Content

Open-faced toasted tomato parm sandwich

This post may contain affiliate links and/or codes. You won’t pay anything extra, but I might make a commission.

Looking for a vegetarian alternative to a meatball sub? You need this hot tomato sandwich recipe! My open-faced Toasted Tomato Parm Sandwich is hearty, cheesy, and filling.

Toasted tomato parm sandwich with basil on top

Accidental sandwich

A couple weeks ago I was making the same quick tomato sauce I make a couple times a week. This isn’t the big pot of spaghetti sauce that I make and freeze, this is a single-serving pan of sauce that I throw together whenever I have leftover pasta from the night before.

Chunky tomato sauce cooking in a pan

Only this time, when the sauce was done and it was time to add the leftover penne, I couldn’t find it in the fridge. Turns out my daughter had eaten it the night before, which was totally fine, but now what was I going to do with the sauce? I was starving, so I didn’t want to take the time to make more pasta.

Then I spotted half a baguette on the counter. I thought about all of the meatball subs I’d made for my husband over the years: mozzarella, sauce, and meatballs on a toasted sub roll (or hoagie, or grinder, or whatever you call those sandwiches where you live). Without the meatballs, wouldn’t it just basically be pizza?

This wasn’t pizza sauce, though. This was a super-chunky concoction of fresh cherry tomatoes from my garden, onions, garlic, and a few other ingredients, and it was so much heartier than the sauce that went onto meatball subs. This could be really good!

I sliced the baguette in half and hollowed out the middle, since otherwise the sauce would probably just fall right off. I sprinkled on some mozzarella cheese and toasted the bread, then put the sauce on top. It was delicious!

Chunky tomato sauce on toasted bread

The original sandwich: cheese on the bottom, tomatoes falling off

The secret to making it less messy!

But it was messy. The next time, I tried cooking the sauce down a few minutes longer, plus I added more cheese. And again it was delicious, but still messy.

The third time, however, inspiration struck! You know those pieces of bread I’d been pulling out to make room for the sauce? I put those in the sauce! The bread thickened the sauce even more and helped bind everything together. Perfection! I now had a hearty, open-faced sandwich that didn’t need a fork.

My hand holding the tomato parm sandwich

See? No fork needed. It all holds together!

Tomato Sandwich Recipe Tips

This sandwich is fresh, warm, filling, and bursting with tomato goodness! I’ve given you the measurements for making one lunch-sized serving for one person, but this can very easily be doubled, quadrupled, whatever. You can also make more sauce than you need, and heat it up another day for another sandwich.

Halved cherry tomatoes, sliced onion, basil, and chunks of bread on a wooden cutting board

I’ve started adding Parmesan cheese to the mozzarella, or just using a pre-shredded Italian blend when I have it. I mean, how much work do I want to do when I’m just making lunch for myself?

Cherry and plum tomatoes in a bowl

Even though it’s 93 degrees as I’m writing this, and I have plenty of fresh tomatoes to use from my garden, this is also a great tomato sandwich recipe for the winter, because cooking the tomatoes down and adding other ingredients can help improve the flavor of a grocery-store tomato in winter. I’ve made this plenty of times in the depths of winter with a container of cherry or grape tomatoes from the store and it still tasted great!

Tomato parm sandwich with shredded cheese on top on aluminum foil in a toaster oven

Heat is also a consideration if you don’t want to heat up your entire oven for one little sandwich, which is why I love my Panasonic Flash Xpress, the best toaster oven I’ve ever owned.

A note on the tomato paste: who wants to open a can of tomato paste when you only need a tablespoon? Nobody. So buy a tube of it. It’s the handiest thing ever! It keeps for a really long time, and when I need a little tomato paste I just squeeze out what I need!

And now, for an evil alternative: you can make this sandwich with leftover garlic bread!

Looking for a tomato sandwich recipe that’s much quicker, like two-minutes-and-done quicker? Try the world’s best tomato sandwich!

Yield: 1 serving

Toasted Tomato Parm Sandwich Recipe

This open-faced, vegetarian sandwich is hearty, warm, and filling! Make it for one, or make it for a crowd. 

Prep Time 5 minutes
Cook Time 15 minutes
Total Time 20 minutes


  • 1 tsp olive oil
  • 1/2 small yellow onion
  • 1 clove garlic
  • 1 sprig fresh basil
  • 1/2 slice sub roll or baguette, or even garlic bread, about 5" long
  • 1 pinch red pepper flakes
  • 1 tbsp tomato paste
  • 1/2 cup tomato puree or plain tomato sauce
  • 1/4 cup shredded mozzarella cheese
  • kosher salt
  • pepper


  1. Pre-heat oven to 400 degrees (or, if you can, use a toaster oven)
  2. Cut the yellow in half and slice about 1/4-inch thick, halve the cherry tomatoes, and roughly chop the garlic
  3. Pull off a few leaves of basil and set aside for garnish, leaving the rest on the sprig
  4. Remove the insides from the roll or baguette, tearing into 1-inch pieces
  5. Heat 1 teaspoon of olive oil in a sauté pan or skillet over medium heat
  6. Add the onions and cook, stirring frequently, for about 3 minutes, or until they are beginning to soften (browning is OK, but don't let them burn)
  7. Add the garlic, a pinch of red pepper flakes, and a little salt and pepper and cook for 1 minute, stirring constantly
  8. Add 1 tablespoon of tomato paste and cook, stirring constantly, for one minute more, or until the tomato paste is mixed in with the onions
  9. Add the tomatoes, tomato purée (or sauce), and the sprig of basil and raise the heat to medium-high
  10. Cook, stirring frequently, for 5 minutes
  11. Add the bread pieces and cook for another 2 minutes or so, until sauce is very thick
  12. While the sauce cooks, put the slice of roll or baguette into the oven and toast it lightly, about two minutes
  13. Remove the pan from the heat, and carefully take out and discard the sprig of basil
  14. Taste the sauce and add more salt and pepper, if needed
  15. Spoon the sauce onto the toasted bread, and sprinkle with the cheese
  16. Put the sandwich on a piece of tinfoil or a baking pan and put it back in the oven for 1-2 minutes, until cheese is melted
  17. Tear the remaining basil and scatter on top of the sandwich as a garnish
  18. Serve immediately


Buying tomato paste in a tube is great for when you only need a little! Also feel free to add some shredded Parmesan or Romano cheese to the mozzarella, or use a pre-shredded Italian mix. 

Did you make this recipe? I'd love to see it!

Please leave a comment, a great star rating, or share what you made on Instagram, tagging @amyoztan. It really helps me out!

Privacy Policy ~ Full Disclosure ~ Disclaimer
Skip to Recipe