Grilled Cheese with Caramelized Onions

1. 1

   Heat the canola oil and 1 tablespoon butter in a large saute pan over medium heat.

2. 2

   When the butter is melted, add the onions and cook, stirring occasionally, until dark brown and caramelized, about 25 minutes.

3. 3

   Add the vinegar, sugar and 2 tablespoons water, scrapping up any dark bits that have accumulated on the bottom of the pan.

4. 4

   Continue to cook until all the liquid has evaporated.

5. 5

   Transfer the onions to a bowl and reserve.

6. 6

   Butter 1 side of each bread slice.

7. 7

   Lay 6 slices butter-side down on a work surface.

8. 8

   Top each with 2 slices of Gruyere, a dollop of the onions and 2 more slices of Gruyere.

9. 9

   Top with another slice of bread, butter-side up.

10. 10

    Heat a cast-iron griddle over medium heat.

11. 11

    Add the sandwiches and cook until the cheese begins to melt and the bread is golden brown, 2 to 4 minutes.

12. 12

    Flip and continue to cook until golden brown and the cheese is melted through, 2 to 4 minutes.

13. 13

    Cut in half and serve immediately.

* Per serving · 4 servings · Values may vary.