I’m extremely frugal, so in my eyes, wasting food is criminal. I always try to cook with ingredients already on hand, and this grilled cheese is a result of that. Using leftovers and items I needed to get rid of, I whipped up this cheesy and delectable grilled cheese. The caramelized onions stole the show, but the truffled fried potatoes came in a strong second. Of course, the gooey Gruyere cheese played its part, too!
1-2 tbsp. butter
1 red onion, sliced into thin strips
4 tsp. olive oil, divided
1 potato, rinsed, then cut into 1/4-inch-thick pieces, seasoned with salt and pepper
1-2 tsp. white truffle oil
4 cremini mushrooms, stems removed, thinly sliced, seasoned with salt and pepper
1 tomato, thinly sliced
Swiss and Gruyere cheese, desired amount
Pats of butter, to spread on top of buns
4-6 mini hamburger buns
Heat a medium skillet over medium heat, then add butter and melt to coat the bottom of the pan. Add sliced onions and mix with the melted butter. Spread the onions out evenly in the pan and cook, stirring occasionally. Reduce heat if onions look like they’re starting to burn or dry out. Let onions cook 30-45 minutes, continuing to stir, until the onions start sticking to the pan and have a rich, browned color. Remove caramelized onion from the heat and set aside.
While onions are cooking, heat another skillet over medium heat, then add 2 tsp. olive oil. Add sliced, seasoned potatoes and spread out evenly in the pan. Add white truffle oil and stir, to coat all the potatoes. Cook potatoes, flipping occasionally, until tender and nicely browned, about 20-25 minutes. Increase heat to medium-high if potatoes aren’t browning. Remove potatoes from heat and set aside.
Warm another small skillet over medium heat. Add 2 tsp. olive oil, then add sliced, seasoned mushrooms. Saute until mushrooms soften, about 5 minutes. Remove from heat.
To prepare the sandwich, take the bun and turn the top and bottom pieces upside down, so the sesame seeds on the top of the bun are facing upwards. Stack the bottom bun with shredded cheese, then sliced mushrooms, sliced potatoes, caramelized onions, sliced tomato, and top with more cheese (it will get messy and difficult to keep all the ingredients on the small bun, so push down on the bun if you have to). Place the top bun on the sandwich, with the seeded side facing down. Place a pat of butter on the bottom and top buns.
Heat a grill pan over medium heat, then place sandwich on heated surface. Cook until cheese melts and the bottom of the bun is nicely browned; flip sandwich and cook other side until cheese melts and bun browns. Remove grilled cheese from pan and let rest for a minute or two, then slice in half. Serve.