Kale and Caramelized Onion Veggie Panini

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This savory veggie panini with caramelized onions makes the vegetarian lifestyle easy – and downright delicious. The fontina cheese oozes out of the sandwich, the bread is warm and crispy, and the sautéed kale adds a complementary lightness.

Have you ever made a veggie panini? If not, let’s change that today shall we? I promise it will leave you completely satisfied and possibly a little obsessed.

This vegetarian panini recipe has everything you want in a vegetarian sandwich:

• Crispy outside
• Melty inside
• Savory
• Meatless (and you don’t miss it!)
• Low prep time

Plus, it’s a delicious way to get some extra greens into your diet, and is a healthified, dressed-up version of grilled cheese. It’s also super easy to make! An under 30 minute vegetarian meal!

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How could you not like that? 🙂 It can also easily be made on a weeknight because it takes less than 30 minutes to make.

In fact, my family (including my two kids!) loved it so much, it has now made it into our regular weeknight dinner rotation!

Before we get to the goods, let’s talk about choosing the right ingredients. 

The Best Bread for Paninis

The best panini bread is one that’s hearty and can take heat well. So that includes baguettes, focaccia, or ciabatta. 

At your grocery store, you’ll probably find bread labeled “panini bread,” which is usually one of the three types I just mentioned, so you can also just look for that. Sourdough paninis are really good as well. 

One thing that I think people overlook with panini sandwiches is that the bread can actually contribute to the overall flavor. So don’t just think of it as “holder of the veggies and cheese.”

Instead, think of the bread as equally important of an ingredient as the rest. Imagine what an herb-infused bread like rosemary or oregano would do to the overall flavor!

Beyond that, the general rule of thumb for choosing a good panini bread is the denser the better. 

How to Make a Veggie Panini

I wanted to make the sandwich a bit more savory than sweet, so I opted for roasted garlic, sautéed spicy kale, and caramelized onions.

Recipe Ingredients

• 2 tsp extra virgin olive oil
• Extra virgin olive oil spray
• 1 8oz box baby kale (or 8oz of whole kale, chopped thinly)
• 2 cloves garlic, minced
• 1/8 tsp crushed red pepper
• Salt to taste
• 1 red onion, sliced thinly
• Fontina cheese: 1 oz per sandwich
• Good, whole grain, panini bread

Step by Step Instructions

Step 1: Sauté the kale with the garlic, crushed red pepper, olive oil, and a dash of salt until it’s wilted.

Step 2: In 1 tsp olive oil, sauté the onions until they are caramelized and golden brown.

Step 3: Assemble your sandwiches! Spread 1 clove of roasted garlic on one side of the sandwich. Top with 1 oz fontina cheese per sandwich, 1/4 of the caramelized onion mixture, 1/4 of the kale, and a dash of salt/pepper to taste.

Step 4: Grill in a panini press or a skillet until the cheese is melted and the bread is crispy on the outside/soft on the inside.

How to Make a Veggie Panini Without a Panini Press

It’s absolutely possible to make a delicious panini without a panini sandwich maker. There are a couple different ways actually:

How to Cook a Panini in the Oven 

These are lovingly referred to as sheet pan paninis, and they give you that crispy outer crust without any fancy equipment. 

You fix the sandwich like you normally would and place it on a lined baking sheet. Then comes the panini-lover’s hack:

Place another baking sheet on top of it – yes, directly on top of the sandwich – and place a heavy stock pot or dutch oven on top of that to act as a weight or “press” for your panini.

Bake at 350 degrees for about 20 minutes and enjoy.

How to Make a Panini on the Grill 

This is the perfect way to cook a panini when you’re grilling out in the summer or going camping. It adds a slight smoky flavor that really pairs well with the other ingredients. 

All you need is some aluminum foil, butter, and a brick. Yep…a brick!

Brush melted butter on the aluminum foil (to prevent sticking), and wrap your sandwich in it. Place it on the grill and place a brick on top of it. Cook for about 5 minutes on one side, flip, place the brick back on, and cook for another 5 minutes. 

As you can see, there are multiple ways to make a panini at home. Just choose the one that works best for you!

Tips for a Perfect Vegetarian Panini Sandwich Every Time

• Take the time to roast your veggies if you can. The roasted garlic really kicks this veggie panini up a notch. 
• I’ve found that vegetarian panini recipes pair well with pesto. Honestly, I haven’t had a sandwich yet that wasn’t improved with pesto! And it’s a quick and easy way to make your panini Italian-style. 
• If your goal is to make a copycat version of a veggie panini from Panera, use tomato basil bread. Seriously, you’ll thank me later. 
• If you have problems with the bread sticking, you might want to butter your panini press (if you’re using one). 
• If you have kids, this is a great way to sneak in some extra veggies into their diet without them noticing. For especially picky kids, try chopping up the kale super small and cooking it down completely before mixing with the cheese and other ingredients in the sandwich. You can also leave off the roasted garlic if it’s too strong for your kids!

This kale and roasted garlic version is one of the best vegetarian panini recipes I’ve ever made. You have to try it! And if you liked this one, you’ll drool over these, too:

• Goat Cheese, Pear and Arugula Panini
• Mediterranean Style Panini
• Gourmet Grilled Cheese Sandwich Panini with Pear

Oh and if you’re wondering what to eat with a vegetable panini, try pairing it with a healthy coleslaw, side salad, or even a pasta salad!