Preheat oven to 200 degrees F and arrange a baking sheet in the oven.

Warm olive oil in a large nonstick skillet over medium heat.

Add red and green bell pepper strips to the skillet.

Cook, stirring occasionally, until browned and tender, about 8-10 minutes.

Transfer peppers to a plate or bowl and set aside.

Wipe out the skillet.

Lightly spread butter on one side of each tortilla (optional).

Lay tortillas, buttered side down, on a work surface.

Arrange 1/2 cup of cheese on half of each tortilla, leaving a 1-inch border.

Arrange bell peppers and pulled pork on top of the cheese.

Fold the tortillas in half over the fillings.

Rewarm the skillet over medium heat.

Add 2 quesadillas to the skillet and cook, covered, until golden brown on the bottom, about 2-4 minutes.

Carefully turn the quesadillas and cook, uncovered, until golden brown on the other side and the cheese has melted, about 1-3 minutes.

Transfer finished quesadillas to the baking sheet in the oven.

Wipe out the skillet and repeat with remaining quesadillas.

Cut each quesadilla into 4-6 wedges.

Serve with salsa (optional).