Grab a large pan, set it over medium heat, and pour in a tablespoon of olive oil. Toss in the chopped onion and cook for about 3–4 minutes, until it starts to look soft and see-through. Add the garlic and mushrooms next. Let them cook down for 8–10 minutes you’re waiting for the mushrooms to release their water and for that water to mostly cook off. Sprinkle in some salt, pepper, smoked paprika, and oregano. Stir everything together, then take the pan off the heat and let it cool for a few minutes.

In a large bowl (or use a food processor if you prefer), combine the mushroom mixture, black beans, oats, breadcrumbs, shredded cheese, and the egg. If you’re using a bowl, mash it up with a fork or potato masher. If it’s looking too wet, throw in a bit more breadcrumbs. If it’s dry and crumbly, add a splash of olive oil or mash a bit more of the beans.

Split the mixture into four parts and form them into burger-sized patties. Lay them out on a tray lined with parchment paper. Stick the tray in the fridge for at least 15 minutes this helps the patties hold together better when you cook them.

Heat up a skillet or grill pan on medium. Add a bit of olive oil and lay the patties down gently. Cook each one for about 4–5 minutes on each side, until they’re nicely browned. If you want cheese melted on top, add it in the last minute of cooking and cover loosely so it melts faster.

While the burgers are cooking, toast your buns in a dry skillet or pop them in the oven for a couple of minutes. You want them warm and a little crisp, not burned.

Start with a lettuce leaf on the bottom bun so things don’t get soggy. Add the mushroom patty, then stack on some tomato slices, red onion, and whatever sauce you like mayo, mustard, spicy aioli, up to you. Cap it with the top bun and serve right away while it’s still hot.