Tomato Sandwich Crostini

Tomato Sandwich Crostini- Summer’s favorite tomato sandwich is transformed into an open faced, handheld bite.

August 31, 2025 by Nicole Collins

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Today, we’re making Tomato Sandwich Crostini!

Tomato sandwiches are one of my favorite things about summer eating. And honestly, I make tomato sandwiches all year long to get me through those bone chilling months.

There are so many schools of thought when it comes to the perfect tomato sandwich. The bread: toasted or untoasted? Cheese or no cheese? Multiple layers or tomato or one thin layer. For me, I like toasted bread, cheddar cheese, one thin layer of tomato, and double mayo.

One day long, long ago, I was craving a tomato sandwich but didn’t have any sandwich bread. What I did have, though, was some baguette. So, I sliced up that baguette into little crostini, assembled little open faced baby tomato sandwiches, and my life was changed. IT. WAS. SO. GOOD.

The only problem with that simply delicious little bite is that I couldn’t for the life of me figure out how to make it pretty enough to put on the blog. We’re talking years of assembling and reassembling these little bites trying to make them beautiful.

I was actually going to make these for TikTok (you know I post over there every day, so if you’re not following me there you totally should be!), but then I decided at the last minute that we were just going to go for it. Today, we throw that pressure of perfection out the window, make this recipe official regardless of what it looks like, and let the end of summer tomatoes get all the recognition they deserve. I can’t keep this from you any longer. In my brain, there’s a clear order of operations when it comes to food themes for the last half of the year. August = tomatoes. September = apples. October = pumpkin. November = turkey. And December = chocolate mint. So really, it was now or never. And, I choose now!

We’ll start by slicing a baguette into little rounds, drizzling them with some olive oil, and tossing them on a baking sheet to toast. We want to bake these just long enough that they get golden and crisp on the outside while still being soft and chewy on the inside. That’s the absolute perfect texture for crostini in my opinion.

Once our bread is toasted, we’re going to top each slice with a schmear of mayonnaise. We’re not going to do anything to doctor it up…just straight mayo. They beauty of a tomato sandwich is that it’s classically simple, and these crostini are no exception.

Next, we’ll do the sharp cheddar. This is the part of the recipe that stumped me for years on how to properly present it. So, this is where we just go for it. We can either thinly slice some extra sharp cheddar cheese off the block OR we could even use slices of sandwich cheese. Normally, I’d just tear little bits of sandwich cheese to put on top of the bread. But for these, we’ll act like we’re sophisticated and politely cut each slice of cheese into 9 little rectangles. Or if you’re using a block, I’ll use a cheese shaver to get nice thin cuts. Uniform cuts make all the difference! Then, we’ll lay one piece of cheese on top of the mayo, and it’s time for the tomatoes.

Again, when I making these for myself, I just haphazardly toss slices of tomato on top of the cheese. But for these, I made two small decisions that make all the difference in the beauty department. 1. I used a mix of heirloom tomatoes so we could have a variety of color on the platter. And 2. I cut the tomato slices into little wedges to make them look a little fancier. So, lay the tomato wedges on top of the cheese, season them with a pinch of flaky salt and pepper, and that’s all there is to it.

For presentation purposes, I garnished these with some fresh chives. But honestly, they don’t need them. There’s something about the olive oil drizzled crostini mixed with the mayo schmear that makes the bread almost buttery. Then, you have that sharp cheddar and acidic tomatoes that balance the richness perfectly, and it’s just such a lovely bite. These are so simple, but I’m telling you…I dream about these. And what a great appetizer for a summer send off or Labor Day barbecue!

Alright, everyone! I can’t wait to hear what you think of these. I know you’re going to love them!

I hope you enjoy! And, let’s eat!

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Tomato Sandwich Crostini

Serves: 36          Print

Ingredients:

• 1 baguette, cut into ½ inch thick slices (36 slices)

• 1/3 cup mayonnaise 

• 4 slices sharp cheddar sandwich cheese (or 4oz block extra sharp cheddar cheese, thinly sliced)

• 6 slices heirloom tomato, cut into ¼ inch thick slices

• Olive oil, for drizzling

• Flaky salt and pepper, to taste

• Mince chives, for garnish

Directions:

1. Prepare the baguette: Preheat oven to 375 degrees. Arrange baguette slices on a parchment paper lined baking sheet, and lightly drizzle the top side of the bread with olive oil. Bake for 8-10 minutes until the bread is lightly golden.

2. Meanwhile, cut each slice of cheese into 9 pieces. Cut each slice of tomato into 6 wedges. 

3. Assemble the crostini: Schmear mayo evenly over the top side of each piece of baguette. Top each crostini with one piece of cheese and one tomato wedge. Finish with flaky salt and pepper, to taste. Garnish with minced chives, if desired. Serve immediately. 
   

Recipe notes:

*I typically use a baguette from Aldi, and I get a full 36 slices of crostini.

*This recipe can be easily scaled down. I’ll use a quarter baguette for girl dinner all the time!

*Sometimes, I use sandwich cheese. Sometimes, I use block cheese. If I use cheese from a block, I’ll usually use a cheese shaver to get nice, thin slices. Either way, the sharper the cheese, the better. 

*You can totally use regular tomatoes, but heirlooms are just so beautiful!