Add 1-2 tsp of olive oil to a skillet over medium-low heat. Build quesadillas one at a time by laying a tortilla in the pan and covering with 1/4 cup of Swiss cheese. Just as the cheese begins to melt, add 2 oz of corned beef to one-half of the tortilla. Top the corned beef with 1-2 Tbsp of sauerkraut and 1/4 cup cabbage slaw. Fold the tortilla in half and continue cooking until each side is golden brown, flip as needed. Add 1 tsp of oil to the pan in between each quesadilla.