Piri Piri Mushroom Smash Burger

Piri Piri Mushroom Smash Burger

A good old fashioned cheeseburger, with a little extra warmth and flavour. Our Lion's Mane Piri Piri sauce perfectly enhances the mushroom topping and plays a supporting role in the burger patties and the mayo! Don't question the American cheese, it's for the best.


Ingredients (Makes roughly 4 patties):

  • 1-1.5lb Ground Beef
  • 1 Onion, thinly sliced
  • 4 cups mushrooms sliced (we used cremini and shiitake)
  • 4 cloves garlic, thinly sliced
  • American cheese slices
  • Salt
  • Pepper
  • Canola Oil
  • Mayonnaise
  • 5Tbsp Butter
  • Hamburger buns (we used brioche)
  • Lion's Mane Piri Piri


  • Cast Iron Pan/Standard Frying Pan
  • Small mixing bowl


STEP 1: In a small mixing bowl, mix 3/4 cup mayonnaise with 3 tbsp of Lion's Mane Piri Piri (or more depending on your taste). Set aside in the fridge. Slice mushrooms, onion, and garlic, and set aside.

STEP 2: Heat your pan over medium high heat, and add 3 tbsp of butter once hot. Allow to melt, then add your thinly sliced onions and a pinch of salt. Stir to combine and cook until caramelized. Remove from pan and set aside.

STEP 3: Add another 2 tbsp of butter to the pan and allow it to brown slightly. Add mushrooms, a pinch of salt, and cracked black pepper. Stir to combine. Once mushrooms are softened, turn heat down to medium-low and add garlic. Cook down for a couple more minutes, then add 3-4 tbsp of Lion's Mane Piri Piri and your cooked onions back to the pan. Stir until sauce is fully incorporated and allow to heat for another minute. Remove from pan and set aside.

STEP 4: In a mixing bowl, add ground beef, a generous pinch of salt, pepper, and 2 tbsp Lion's Mane Piri Piri. Mix well by hand until fully combined. Divide beef into 4 evenly sized balls (don't flatten yet). Set aside and bring your pan up to high heat. When hot, add a splash of canola oil and swirl to coat entire pan. Place 1 ball into the center of the pan, and smash it down with the bottom of a small mixing bowl (you can also use a spatula if you prefer). Cook 1 minute, then flip. Cook another minute, adding 1 slice of American cheese halfway through to melt. *Make sure to cook 1 patty at a time to avoid overcrowding the pan. Set patties aside when done, then remove excess oil from pan.

STEP 5: Using the same pan, place your hamburger buns face down to toast making sure not to burn them.

STEP 6: Build your burger in the following order:

  • Place 1 patty on bottom bun
  • Add desired amount of mushroom topping
  • Add 1 slice of American cheese
  • Add second patty if you want to party
  • Dress top bun with a spoonful of Piri Piri mayo mixture and place on top
  • Enjoy!