In a small bowl, whisk together the mayonnaise and gochujang or chili garlic sauce until smooth and evenly coloured. Cover with plastic wrap and refrigerate until ready to use.

Add 1 tablespoon of the oil to a medium sized, non-stick skillet placed over MEDIUM HIGH heat. Add the drained kimchi to the pan and stir-fry until the kimchi is browned around the edges and fragrant. Transfer to a bowl and cover to keep warm. Brush the cut sides of the pretzel rolls with the remaining oil and grill or toast in the skillet until golden brown. Carefully remove the rolls.

Generously spread the spicy mayonnaise on the cut sides of both the top and bottom halves of each bun. Divide the mixed spring greens or arugula between the bottom halves of the buns. Lay one burger patty on each. Divide the stir-fried kimchi between the burgers and add the top halves of the buns. You may want to drive two skewers down about 1 inch apart near the center of the burger to help hold it together as you cut it in half. If you prefer to serve it whole, just use one skewer in the center.