Instructions

• Heat a nonstick skillet over medium-high heat.
• Add about 1 tablespoon of the olive oil to the skillet, then add the sliced onion. Stir to coat.
• Cook the onion, stirring every 2 minutes, until caramelized, about 10 minutes. You may cover the pan to speed cooking; lower the heat if the onion is browning too quickly.
• Once the onion is caramelized, add the sliced baby portobello mushrooms, the 1 cup diced pickles, the remaining 1 to 2 tablespoons olive oil (to total 2–3 tablespoons used), and 1 teaspoon pickle juice. Stir to combine.
• Cook the onion-mushroom-pickle mixture, stirring every couple of minutes and optionally covered to save time, until the vegetables are softened and wilted, about 10 minutes. Turn off the heat and set the mixture aside.
• While the vegetables cook, make the fry sauce: in a medium bowl combine 1/2 cup ketchup, 1/4 cup mayo (or Miracle Whip; use vegan mayo to keep vegan), about 3 teaspoons pickle juice (or to taste), and a pinch of onion powder (optional). Whisk until smooth and taste; adjust the pickle juice if desired.
• Split the 6 slider buns (or Hawaiian rolls) and generously spread fry sauce on both cut sides of each bun.
• Fill each bun with the caramelized onion and mushroom mixture, close the sliders, and serve immediately.