Preheat grill on medium high heat.
Pickled Shitake Mushrooms: In a saucepot over medium high heat combine shitake mushrooms with rest of ingredients and bring to a boil. Cook for five minutes until sugar is dissolved and remove mushrooms from brine. Let mixture cool and store in the fridge for at least 30 minutes.
Gochujang Mayo: In a bowl combine all ingredients and mix until well combined. Set aside in fridge.
Grill burgers approximately 2-3 minutes per side for a medium-rare burger, or until 160⁰F for well done. Before flipping, brush burger with Get Sauced Honey Garlic Sauce and repeat on the other side until nicely glazed.
To assemble brush top and bottom of bun with Gochujang Mayo. Place burger on bottom bun then cover sliced with radishes. Add watercress and top with a heaping tbsp of pickled mushrooms. Cover with top bun.
Serve with a side of Cal & Gary’s Sea Salt Crinkle Kettle chips.