Gluten-Free Portobello Black Bean Veggie Burgers
Hearty vegetarian burgers built on mashed black beans and meaty portobello mushrooms, bound with eggs and panko for a satisfying crust. Broccoli and garlic add nutrition and depth, while parmesan and worcestershire provide umami complexity. Perfect for weeknight dinners or casual entertaining when you want something more substantial than a standard veggie patty. This version respects the mushroom's earthiness rather than masking it, creating burgers that appeal to meat-eaters and vegetarians alike.
Ingredients
- 2 cup portobello mushrooms, cubed with gills removed
- 2 cup cooked black beans, rinsed and divided
- 1 cup fresh broccoli, minced
- ½ cup red onion, minced
- 3 eggs, XL beatenflax eggs (3 tablespoon ground flax plus 9 tablespoon water, mixed and rested 5 minutes)1:3 ratiovegan
binding agent
Full guide → - ⅝ cup panko breadcrumbs, or gluten-free pankocrushed almonds or oat flour0.625 cup to 0.75 cupgluten-freegluten-free
binding; increases nuttiness
Full guide → - 1 tablespoon montreal steak seasoning
- 1 tablespoon worcestershire sauce, vegetarian-friendly without anchoviestamari or soy sauce1:1 ratioveganadds glutenadds soy
umami base; check label for anchovies
Full guide → - 2 tablespoon garlic, minced
- ¾ cup parmesan cheese, fresh grated, vegetarian-friendly
- olive oil, for cooking
Instructions
- 1
Mash one cup of black beans in a large bowl, leaving some chunks.
- 2
Combine mashed beans with mushrooms, remaining beans, broccoli, garlic, onion, worcestershire, and steak seasoning until coated.
- 3
Add eggs, cheese, and panko, mixing gently until combined.
- 4
Heat oil in a medium non-stick pan over medium heat until shimmering.
- 5
Wet your hands and scoop half-cup portions, shape into burger patties, pressing firmly to hold shape.
- 6
Cook each burger three to five minutes per side until golden brown and crusty.
- 7
Serve with hummus, guacamole, or steak sauce.
Tips
Saute mushrooms first to remove excess moisture and concentrate their umami flavor; this prevents soggy burgers.
Dampen hands before shaping to prevent sticking and help the mixture hold together during cooking.
If patties fall apart in the pan, add one more tablespoon of panko to the remaining mixture before shaping.
Good to Know
Refrigerate cooked burgers in an airtight container up to four days. Freeze uncooked patties on a sheet tray, then in a freezer bag up to three months; cook from frozen, adding two to three minutes per side.
Mix the burger mixture up to one day ahead and refrigerate. Shape patties up to four hours before cooking.
On burger buns with hummus, guacamole, steak sauce, lettuce, tomato, and pickles. Pairs well with roasted fries, coleslaw, or a simple green salad.
Common Mistakes
Do not skip the shimmer step to avoid oil that is too cool, which yields greasy burgers instead of golden crust.
Do not overmix after adding eggs and panko to avoid dense, rubbery texture; gentle stirring creates tender patties.
Do not skip mashing one cup of beans separately; this creates structural integrity without food-processing the entire mixture into paste.
Substitutions
Dairy-Free Swaps
Vegan Options
binding agent
Full guide →umami base; check label for anchovies
Gluten-Free Swaps
binding; increases nuttiness
Full guide →General Alternatives
FAQ
Can I make these vegan?
Yes. Replace eggs with flax eggs and use vegan parmesan or nutritional yeast. Check worcestershire for anchovies and choose a vegetarian brand. The final patty will be slightly more crumbly but holds together if you refrigerate before cooking.
What if the mixture is too loose to shape?
Add one tablespoon of panko at a time until the mixture holds its shape when pressed. Over-moistness comes from unsauteed mushrooms or excess liquid in the beans; drain them thoroughly.
Can I freeze uncooked burgers?
Yes. Shape patties, freeze on a sheet tray two hours until solid, then transfer to a freezer bag up to three months. Cook from frozen, adding two to three minutes per side, until the internal temperature reaches 160F if using eggs.