Charred Broccoli Rabe Sandwich with Balsamic Onions & Red Pepper Sauce

I am not a big sandwich girl, and that’s because I find vegetarian sandwiches to often be lacking, or feel like an afterthought – so when I set out to make this broccoli rabe sandwich, I knew I wanted to make it craveable.

There are a few things that determine (to me) what make a good sandwich. And this can vary person to person, because sandwiches are deeply personal and arguably, highly opinion-based. But for me, a good sandwich includes:

1. A saucy element, a sturdy main, a flavor enhancer and a cheese. I didn’t list a protein here because I’m a simple girl, and a vegetarian sandwich can make my heart sing (if it’s done right!)
2. It must be pressed enough that biting it, and getting everything in one bite, is not difficult. Making bites a battle is a problem – and I’m looking at you, Burger Industry!
3. The bread must have a crisp aspect, but also a light center. Meaning the sauce can’t dampen and cause a soggy sandwich, the bread can’t be too toasted, and the bread can’t be too thick. A lot rides on the loaf.

So after all of my sandwich-crusading, I wanted to take every aspect that I value and put it into one broccoli rabe sandwich. This sandwich has it all – a bright, sweet & spicy red pepper sauce, a sturdy, bitter and charred broccoli rabe center, balsamic glazed onions (which are amazing) and a smoked mozzarella. The smoked part is not mandatory, but if you can get it…it’s so so good.

Read on for how to make this sammie – for the flavor you get, it’s really quite simple.

What is broccoli rabe?

Broccoli rabe is a generally bitter green with a bad rap. I find it to be one of the most delicious greens, and it’s all in how you use it!

Also known as rapini, broccoli rabe is a cruciferous vegetable, and its buds sometimes resemble broccoli. It tends to flower in the early spring harvest season, and those are even more delicious. This vegetable can be a bit stiff and hard to handle, so I recommend cutting it down the same way we do with kale, making the bites easier to cook and, of course, easier to eat.

Ingredients you will need for this broccoli rabe sandwich

• 1 medium baguette, sliced into 3 pieces
• 1/2 cup roasted red peppers, drained
• 1 & 1/2 teaspoons Calabrian chili paste
• Kosher salt and freshly ground black pepper to taste
• 1 medium yellow onion
• 1 tablespoon salted butter, or vegan butter alternative
• 1 tablespoon olive oil, plus more as needed
• 1 tablespoon balsamic glaze
• 1 pound broccoli rabe
• 3 ounces smoked mozzarella sliced

How to make the roasted red pepper sauce

What I love about this sauce is it’s easy, and you can use it in so many other applications.

To make it, pull out a small blender and add the red peppers, calabrian chili paste and a shallow 1/4 cup of water. Blend until you have a smooth sauce. Season with kosher salt and black pepper to taste. Set this aside, it’s delicious.

How to make and assemble the rest of the sandwich

The rest of the sandwich really relies on timing, with the longest element being the onions. The good part is everything is done in one pan, so you just need to let things take turns.

After the red pepper sauce is done, thinly slice the onion and place a large sauté pan over medium heat. Melt the butter in the pan, then add a tablespoon of olive oil. Add the onion and season with a pinch of salt. Cook, stirring occasionally, to let the onion almost caramelize. True caramelization takes up to 40-45 minutes, but in the interest of time, I cooked mine for about 20-25, letting the onions get soft, jammy, and lightly brown.
When the onions are almost done, drizzle the balsamic glaze over them. Give everything a quick mix in the pan, then transfer to a small bowl.

Cut the broccoli rabe in half, then into long strips, slicing through the center of the stem pieces. Add the broccoli rabe to the same pan you cooked the onions, and top them with a drizzle of olive oil and pinch of salt.
Shake the broccoli rabe around the pan, letting it charr in some places. Cook for about 3 minutes on each side before removing from the pan.

Assemble each sandwich with the red pepper sauce first, then a layer of broccoli rabe, then slices of smoked mozzarella. Broil this in an oven or toaster oven for 5 minutes, or until the cheese is melty. Add the onions to the other slice of the baguette, smash together, and eat.

What is the best bread for this broccoli rabe sandwich?

Like I mentioned above, when it comes to sandwich bread, I like something that can hold up to the ingredients I’m using, but also something that is light and easy to bite into. For this particular sandwich, where the crunch aspect is VERY important, I like to opt for a baguette. However, that doesn’t mean a baguette is the be-all end-all of broccoli rabe sandwiches everywhere, here are other great options that you can use:

• Ciabatta – you could even make this into a panini!
• Sourdough – just make sure the pieces are thick enough to hold up to the sauce and onions.
• Focaccia – would be so so delicious here.

FAQS

Looking for other sandwich recipes?

I don’t have many, and that’s because I have high sandwich standards. here are a few I particularly love:

And that’s it for this charred broccoli rabe sandwich!

If you make it, please tag me on Pinterest or Instagram so I can see! It’s my favorite thing to scroll through stories and see what you all are making.

And of course feel free to leave any questions, comments or reviews! This is the best place to reach me, and I’d love to hear from you <3