Balsamic Portobello Burgers with Carmelized Onions

by Stacy

Post image for Balsamic Portobello Burgers with Carmelized Onions

You know what’s awesome? Burgers.

Hamburgers, turkey burgers, salmon burgers, black bean burgers – put a slab of protein on a bun, preferably cooked on a grill outside, and call it summer. Add the first tomatoes, cucumbers, and melons of the season, and you have the perfect recipe for the Fourth of July.

As much as I love my black bean burger recipe, it does take some actual planning. Whether I soak dried beans myself or use a can, they require some mixing and forming. That would be great if I had ten minutes to spare, but I have this baby who requires supervision.

I could just grab a box of frozen veggie patties, but A) compared to the homemade kind they taste of disappointment, and B) have you read the ingredients on those things?

So what’s a vegetarian burger fan to do?

portobello mushroom burger

All hail the mushroom.

You know what’s in a Portobello mushroom? Just mushroom. They’re also great for taking along to a friend’s house. So easy!

You can grill these bad boys (or elect a Grill Master to do so for you) or cook them in a frying pan or grill pan on the stove. (If you’re not a meat-eater and have to share a meaty grill, put it on a piece of tinfoil.)

Carmelized onions make everything better, so I threw on a mess of those, and I had some red pepper hummus in the fridge, so that went on, too. Other good options: pesto, microgreens, or blue cheese.

The photo was taken BB (Before Baby), and my delicious lunch was rounded out by warm red cabbage salad and some arugula.

portobello mushroom burger

For a summer picnic try these tips and recipes:

What’s your favorite summer picnic dish?

print recipe
Balsamic Portobello Burgers with Caramelized Onions
Delicious marinated mushroom caps make juicy vegetarian treats for any summer cookout. Use decent balsamic vinegar – it’s worth it.
  • 1 medium onion
  • 1 clove garlic
  • 2 tablespoons olive oil, divided
  • 1 tablespoon balsamic vinegar
  • 1 large portobello mushroom cap
1.) Peel the onion and slice it in half from root to tip. Slice into half-moons about 1/4 inch thick. Mince the garlic. Wash the mushroom cap and pat dry.2.) Combine the garlic with 1/2 tablespoon olive oil and all the vinegar. Pour over mushroom in a shallow dish (I use a lidded Tupperware container), making sure it’s all coated. Let marinate while you cook the onions. 3.) Place a large skillet over medium-high heat. Add the onion (no oil) once the pan is fairly hot. Stir occasionally until onion starts to brown. Add half the olive oil and stir to coat. Reduce heat and stir occasionally until onions are very soft and brown, at least 30 minutes. Add a few splashes of water to deglaze the pan.4.) Heat another pan (or the grill) and brush with the last of the olive oil. Add the mushroom and let cook, undisturbed, about 5 minutes per side. Pour in any additional marinade and let it reduce. Serve warm on a bun topped with onions.

Prep time: Cook time: Total time: Yield: 1 burger

{ 2 comments… read them below or add one }

Snehal July 1, 2013 at 1:10 pm

I love that balsamic glaze on the mushroom! Portobello is my go-to option for vegetarian grilling as well. Will try it with balsamic next time. And I completely agree – caramelized onions do make everything better!


Stacy July 2, 2013 at 10:02 pm

Let me know how you like it, Snehal!


Leave a Comment

CommentLuv badge

Previous post:

Next post: