For the relish:
2 large heads of garlic, top 1/2-inch cut off
5 tsp. extra-virgin olive oil, divided
1/2 cup roasted red pepper from a jar, drained and diced
1 tbsp. fresh parsley
Coarse kosher salt
For the hot dogs:
6 grilled or toasted hot dog buns
6 grilled all-beef hot dogs
2 oz. Manchengo cheese, grated (I used a lot less than the full 2 oz.)
To make the relish, preheat the oven to 400° F. Place each head of garlic, cut side up, in the center of a square of aluminum foil. Drizzle each with a teaspoon of olive oil, and enclose in the foil. Place the packets on the oven rack. Roast until the garlic is tender, about 45 minutes. Open the packets and let cool for 15 minutes.
Once cooled, squeeze the garlic cloves into a small bowl. Mash enough roasted garlic to measure 1/4 cup. Transfer the 1/4 cup to a bowl. Mix in 3 teaspoons olive oil, red peppers, and parsley. Season with coarse salt and pepper.
Place a hot dog in each bun. Top each grilled hot dog with shredded Manchengo cheese, the garlic relish, and a drizzle of balsamic vinegar. Serve.