Caramelized Onion Grilled Cheese With Miso Butter

Caramelized onion grilled cheese with miso butter. (Kate Sears)

Grilled cheese for dinner feels kind of indulgent, like eating pancakes past 5 p.m. Am I right? (Yes.) Here, I add miso to the butter I use to swipe the interior of the bread slices (avoid getting too excited and adding the miso butter to the outside of the bread—the miso will burn up before the bread gets toasty and golden), and I add caramelized onions, too. This would also be great with onion and rosemary jam instead of the onions.

Serves 2

• 4 tablespoons (1/2 stick) unsalted butter, room temperature
• 1 tablespoon extra-virgin olive oil
• 1 large yellow onion, peeled, halved, and thinly sliced
• 1/2 teaspoon kosher salt
• 1 tablespoon rice vinegar
• 1 heaping tablespoon miso paste (I like white miso, but a darker miso works, too)
• 1 tablespoon whole-grain mustard
• 4 slices good-quality sandwich bread
• 1 cup grated Gruyère cheese (or 1/2 cup grated Gruyère with 1/2 cup grated Gouda for extra umami)
• Cornichon pickles, for serving (optional)

Melt 1 tablespoon of butter in a large nonstick skillet over medium-high heat. Add the oil, onion, and salt and cook, stirring often, until the onion is soft and browned in spots, 8–10 minutes. Stir in the vinegar and turn off the heat. Transfer the onion to a small bowl and set aside (don’t wash the pan).

Mix 1 tablespoon of the remaining butter with the miso paste and mustard in a small bowl. Spread one side of each bread slice with the remaining 2 tablespoons of butter. Spread the other side with the miso butter. Place two of the bread slices, plain buttered side down, in the pan. Divide the cheese and onion evenly between them and top with the other bread slices, plain buttered side up.

Cook over medium-low heat until the bread is golden brown, 4–5 minutes (do not press the sandwich down with a spatula—just let it be). Flip the sandwiches over and cook on the other side until the bread is golden brown and the cheese is melted, 3–4 minutes longer. Transfer to plates and serve immediately with pickles. Lots of pickles.

Excerpted from “Umami Bomb: 75 Vegetarian Recipes That Explode With Flavor" by Raquel Pelzel (Workman Publishing). Copyright 2019. Photographs by Kate Sears.