Ingredients

8 skinless chicken thighs on the bone (about 4 pounds)

3 tbsp. extra-virgin olive oil

1 tbsp. chopped rosemary

2 clove garlic

kosher salt

3 tbsp. unsalted butter

2 onions

2 tbsp. chopped thyme

1 1/2 tbsp. sherry vinegar

Pinch of sugar

Freshly ground pepper

12 flour tortillas

4 oz. blue cheese

Preparation

Step 1In a bowl, toss the chicken thighs with 2 tablespoons of the olive oil, the rosemary, garlic and a generous pinch of salt. Cover and let the chicken stand at room temperature for 30 minutes or refrigerate for 4 hours or overnight.Step 2Meanwhile, in a large, deep skillet, melt the butter in the remaining 1 tablespoon of olive oil. Add the sliced onions, thyme, vinegar, sugar and a generous pinch of pepper. Cook over moderately low heat, stirring occasionally, until the onions are softened, about 30 minutes; add a few tablespoons of water from time to time to keep the onions moist.Step 3Light a grill and preheat the oven to 500 degrees F. Season the chicken with salt and pepper and grill over moderately high heat, turning, until lightly charred and cooked through, about 15 minutes. Let the chicken cool, then pull the meat from the bones and tear into shreds.Step 4Arrange 6 tortillas on 2 large baking sheets. Spoon the onions onto the tortillas and top with the shredded chicken and blue cheese. Cover with the remaining tortillas, pressing to flatten slightly. Bake for about 6 minutes, until the quesadillas are golden and toasted. Transfer the quesadillas to plates and serve right away.Step 5Make Ahead: The unbaked quesadillas can be tightly wrapped in plastic and refrigerated overnight.Step 6Wine Recommendation: Zinfandel’s rich fruitiness makes it a go-to wine for much of Mexican cuisine, since it can balance spiciness as well as stand up to bold flavors. (This holds true even when an interloper ingredient like blue cheese is in the picture.) One great region for Zinfandel is Sonoma’s warm Dry Creek Valley, as evidenced by wines like the plummy 2004 Ferrari-Carano and the chocolate-inflected 2005 Dashe Dry Creek Valley.