Grilled Cheese with Spinach and Pancetta

Deselect All

Vegetable oil cooking spray

6 ounces pancetta, cut into 1/8-inch-thick slices

1/2 cup (1 stick) unsalted butter, at room temperature

2 cups (8 ounces) shredded Monterey Jack cheese

2 cups (8 ounces) shredded mild Cheddar

1 teaspoon kosher salt

1 tablespoon vegetable or canola oil, plus extra, as needed

2 packed cups coarsely chopped baby spinach

16 (1/3-inch-thick) slices country-style white bread