Caramelized Onion Grilled Cheese Sandwiches With Miso Butter
Note: These indulgent sandwiches get a nice tang from whole-grain mustard and a big hit of umami from the miso and the caramelized onions. Grilled cheese for dinner: Why not? Adapted from “Umami Bomb: 75 Vegetarian Recipes That Explode With Flavor,” by Raquel Pelzel.
• 1 tbsp. extra-virgin olive oil
• 1 large yellow onion (1 lb.), thinly sliced
• 1/8 tsp. kosher salt
• 1 tbsp. rice vinegar, preferably unseasoned
• 3 tbsp. unsalted butter, at room temperature (or substitute vegan butter, such as Earth Balance), divided
• 2 tsp. white or dark miso paste
• 1 tbsp. whole-grain mustard
• 4 slices good-quality sandwich bread
• 4 oz. (1 c.) grated Gruyère cheese (or substitute vegan shredded cheese, such as Violife or Daiya)
• Cornichons (aka gherkins), for serving, optional
In a large skillet over medium-high heat, heat the oil until shimmering. Add the onion and salt and cook, stirring often, until the onions start to soften and brown, 5 to 6 minutes. Reduce the heat to medium-low and cook, stirring occasionally, until the onions are deeply browned and sticky, 30 to 45 minutes. Stir in the vinegar. Transfer the onions to a small bowl.
In a small bowl, mix 1 tablespoon butter with the miso paste and mustard. Spread one side of each bread slice with the miso butter. Spread the other sides with the remaining 2 tablespoons butter.
Return the skillet to medium-low heat. Place 2 of the bread slices, plain-buttered-side down, in the skillet. Divide the cheese and onions evenly between them and top with the other bread slices, plain-buttered-side up. (You want the miso butter on the inside of the sandwiches.) Cook until the bread is golden brown, 5 to 7 minutes. (Resist the urge to press the sandwich with a spatula.)
Flip the sandwiches over and cook on the other side until the bread is golden brown and the cheese is melted, 5 to 7 minutes. Transfer to plates and serve with pickles, if desired.
Nutrition information per serving:
Calories 620 Fat 45 g Sodium 960 mg
Carbohydrates 33 g Saturated fat 24 g Total sugars 7 g
Protein 22 g Cholesterol 105 mg Dietary fiber 2 g