Indulge in the ultimate comfort food with these Broiled Sweet Onion Sandwiches—an irresistible blend of savory caramelized onions, melty mozzarella cheese, and perfectly toasted rustic bread. This quick and satisfying recipe pairs sweet onions caramelized in olive oil and a splash of balsamic vinegar with buttery bread, creating a golden, crisp exterior that’s broiled to perfection. Ready in just 30 minutes, these sandwiches are ideal for a cozy lunch or dinner, bursting with rich flavors and simple elegance. Garnish with fresh parsley for a touch of brightness and serve alongside your favorite soup or salad for a meal that’s as effortless as it is delicious.
Preheat the oven broiler to high and position the oven rack about 6 inches below the heating element.
Peel and thinly slice the sweet onions into rings.
In a large skillet, heat olive oil over medium heat. Add the sliced onions, salt, and pepper. Cook, stirring frequently, for 10-12 minutes until the onions are golden brown and caramelized.
Add the balsamic vinegar to the onions and cook for another 1-2 minutes, stirring to combine. Remove from heat and set aside.
Spread butter evenly on one side of each slice of bread. Place the bread, buttered side down, on a baking sheet lined with parchment paper.
Divide the caramelized onions evenly over two slices of the bread (non-buttered side). Sprinkle shredded mozzarella cheese generously on top of the onions.
Place the other two slices of bread on top to form sandwiches, buttered side facing up.
Broil the sandwiches for 2-3 minutes, watching closely to prevent burning. Flip the sandwiches carefully and broil for another 1-2 minutes until the bread is golden and the cheese is melted.
Remove the sandwiches from the oven and let them cool for 1 minute. Optionally, garnish with fresh parsley before serving.
Slice the sandwiches in half and serve warm.
Calories |
1596 | ||
|---|---|---|---|
% Daily Value* |
|||
| Total Fat | 84.6 g | 108% | |
| Saturated Fat | 34.6 g | 173% | |
| Polyunsaturated Fat | 2.7 g | ||
| Cholesterol | 142 mg | 47% | |
| Sodium | 4312 mg | 187% | |
| Total Carbohydrate | 156.9 g | 57% | |
| Dietary Fiber | 11.1 g | 40% | |
| Total Sugars | 26.4 g | ||
| Protein | 53.1 g | 106% | |
| Vitamin D | 0.0 mcg | 0% | |
| Calcium | 1000 mg | 77% | |
| Iron | 7.6 mg | 42% | |
| Potassium | 846 mg | 18% | |
*The % Daily Value tells you how much a nutrient in a serving of food contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.