This is a black bean and Portobello mushroom patty built around real umami — miso paste, soy sauce, tomato paste, and cumin do the heavy lifting. It holds together without eggs or meat, and at 163 calories per patty it fits easily into a week of lunches or dinners. Make a batch on Sunday and you’re set.
Why this recipe works
The two steps that actually make this patty work are roasting the beans and mushrooms before they go into the food processor. Roasting drives off moisture — wet beans and mushrooms are the main reason homemade veggie patties fall apart or turn to mush in the pan. The flax egg (flaxseed meal plus water, left to gel for five minutes) then acts as a binder that holds the mixture together through shaping and cooking without adding any off-flavors. Everything else in the ingredient list is there for flavor, but those two techniques are what give you a patty that actually behaves like a patty.
What can go wrong
- Patties crumble when you flip them: The mixture was too wet going into the pan. Make sure the mushrooms look completely dry on the baking sheet before you pull them — if there’s still liquid pooled around them, give them another 5 minutes. Also let the flax egg sit the full 5 minutes so it gels properly.
- The food processor turns everything into paste: Pulse in short bursts and stop while you can still see distinct pieces of bean and oat. Over-processing removes all texture and the patties will be dense and gummy.
- Patties stick to the pan: A nonstick pan is specified for a reason. If you use stainless or cast iron without enough oil, these will stick. A light spray or thin wipe of neutral oil helps even in a nonstick pan.
- Patties are bland in the middle: Taste the mixture before you form the patties — this is your only chance to adjust salt or seasoning. The soy sauce and miso carry most of the salt, but bean-heavy mixtures can still taste flat before cooking.
- Frozen patties fall apart after reheating: Freeze patties on a flat tray until solid before stacking them with parchment between each one. Thawing in the fridge overnight before reheating gives a much better result than cooking from frozen.
Make-ahead notes
Formed raw patties keep in the fridge for up to 3 days — stack them with parchment between each one and cover tightly. For longer storage, freeze them on a parchment-lined tray until solid (about 2 hours), then transfer to a zip bag or airtight container where they’ll keep for up to 3 months. Thaw overnight in the fridge before cooking; skip the microwave thaw or the texture suffers. Cooked patties reheat well in a dry nonstick pan over medium heat for 2 to 3 minutes per side — skip the microwave here too, it makes them soft and a little rubbery.
Yummy Plant-Based Burger
Ingredients
- 1 can black beans
- 1 large Portobello mushroom
- 1 tablespoon flaxseed meal
- 2 tablespoons water
- ½ cup rolled oats
- 1 tablespoon white miso paste
- 2 tablespoons soy sauce
- 4 cloves garlic minced
- 1 tablespoon tomato paste
- 1 teaspoon onion powder
- 1 teaspoon cumin
- ¼ teaspoon ground black pepper
Instructions
- Preheat oven to 400°F.
- Drain the liquid from the can of black beans and place it on a parchment-lined baking sheet.
- Clean the Portobello mushroom and cut into 1/4-inch thick slices
- Line on a parchment-lined baking sheet (nothing overlapping).
- Bake beans and mushrooms for 30 minutes, flipping once after 15 minutes.
- When the beans and mushrooms have 5 minutes left, prepare a flax egg with the flaxseed meal and water.
- Set aside to thicken.
- When cooked, the beans should be burst, with the whiter parts of the insides showing, and the mushroom should look dry with no residual liquid on the pan.
- After the beans and mushrooms have cooled for 5 minutes, add the flax egg, and all other ingredients to a food processor.
- Process and scrape down the sides once or twice until everything is combined, but there is still good texture.
- Form the mixture into 4 patties and set aside to rest
- Heat a nonstick pan to medium-high heat.
- Add the patties to the pan and cook without touching for 3 to 4 minutes.
- The patties shouldn’t stick and should be golden brown before flipping.
- Flip and cook for an additional 3 to 4 minutes until patties are complete.
- Serve hot on a burger bun with fresh toppings of your choice.
Nutrition
Common questions
Can I use canned lentils or kidney beans instead of black beans?
Yes, but black beans give the best texture and the darkest color, which makes the patty look more like a burger. Lentils work but produce a softer, more crumbly result; kidney beans are a solid substitute.
Do I have to use a food processor, or can I mash by hand?
You can mash by hand with a fork or potato masher. The texture will be chunkier and the patties slightly more fragile, but they’ll still cook up fine — just handle them carefully when flipping.
Can I cook these on a grill instead of a pan?
A grill grate is risky — these patties are firm but not as sturdy as a beef burger and can break apart over open flame. If you want grill flavor, use a cast iron skillet or grill pan set directly on the grates.
Is white miso paste easy to find, and is there a substitute?
Most large grocery stores carry white miso in the refrigerated section near tofu or Asian condiments. If you can’t find it, a small extra splash of soy sauce plus a teaspoon of nutritional yeast gets you close to the same savory depth.
How do I know the patties are cooked through?
Look for a deep golden-brown crust on both sides — that’s your visual cue since there’s no meat thermometer target here. The inside should feel firm when you press the center gently, not soft or squishy.
Can I double the batch and freeze half for later in the week?
Doubling works perfectly and is the most efficient way to use this recipe. Freeze the extra patties raw rather than cooked — they reheat with better texture that way, and you can pull out exactly as many as you need.