Drain your cooked (or canned) beans completely in a strainer, and rinse them clean. You’ll need around 250 g (1/4 lb) of drained beans, which should be about how much is inside a standard 14 oz / 400 g can.

Spread the drained beans on a sheet tray, and pop them into a preheated 350°F/176°C oven for 10-15 minutes to dehydrate them.

• You need to reduce moisture to improve the texture of the patty. If you don’t want to use the oven, you can toast them in a pan until they’ve dried out some and their skin starts peeling.

Add the cooked black beans and bread crumbs to a food processor and pulse a few times until lightly combined and the beans are broken down.

Pour the bean mixture into a bowl and add the black pepper, salt, and msg. Combine.

• Note: Feel free to add other spices or aromatics at this point, if desired (like herbs, onions, garlic, etc).

At this stage, the mixture should still be pretty mealy so we need to bind it with one beaten egg. Add about half the egg to start, then add the cornstarch.

Mix this together until you can form a ball that sticks together. If it feels too wet, add a bit more bread crumbs, or if it's too dry add a little more beaten egg or water.

Divide the bean mixture into four (roughly 65 g) balls.

• Note: This can be stored in the fridge for a couple of days if you want to make it ahead of time.

Mix all burger sauce ingredients until well combined. Taste and adjust if needed.

Gather and slice any toppings you’ll want for the burger. If desired, toast the buns before cooking the patties.

Set a cast iron griddle or pan over high heat, and add a drizzle of cooking oil.

When smoking hot, place a bean ball onto the cook surface. Using a piece of parchment paper as a barrier, smash down the bean ball with a metal spatula until completely flattened (it should be fairly thin and as wide as the bun). Repeat with a second bean patty.

Let the smashed bean patties sear and develop a crust for 2-3 minutes before flipping over.

To one of the patties, add a handful of grated cheese. When melted, add the other smashed patty on top of the cheese to create a double decker patty with melted cheese in the middle.

Remove from the heat and repeat with the remaining 2 bean balls for the other burger.

Assemble the burgers by spreading burger sauce on each bun, adding a layer of pickled onions, tomato, lettuce, topping with the double burger patty stack, and closing it all up. Enjoy warm.