10 ounces Brie, ribs removed, cut into 1/4- inch thick slices
8 ounces Bosc pears (about 2 small pears), thinly sliced
2 ounces arugula (about 2 cups)
Heat a camping stove or grill to medium (about 350° to 375°F), or fit a grilling grate over the direct heat of glowing embers. Combine the mustard, honey, and pepper in a small bowl. Brush one side of tortillas with the oil or spray with the cooking spray; spread the second side of each tortilla with 1 1/2 teaspoons of the mustard mixture.
Place each tortilla, oiled side down, on the camping stove or grilling grate directly over the heat source. Arrange 1/4 of the cheese slices evenly on half of each tortilla; grill until the cheese begins to melt, about 1 minute. Arrange the pears and arugula evenly over the cheese. Using a spatula, fold each tortilla in half to cover the filling, pressing gently to adhere. Grill until the arugula wilts, the tortillas are browned and crisp, and the cheese is melted, 1 to 2 minutes per side. Cut each quesadilla into 2 wedges.