Sheet Pan Pulled Chicken Quesadillas with Roasted Radish Slaw

Name: Sheet Pan Pulled Chicken Quesadillas with Roasted Radish Slaw
Ingredients: 3 Tablespoons Vegetable Or Canola Oil, Divided, Plus More For Brushing On Tortillas; 1 Small Red Onion, Diced; 2 cloves Garlic, Minced; 1 cup Cooked Black Beans; 1 teaspoon Sea Salt, Divided; ¼ teaspoons Ground Black Pepper; ½ teaspoons Ground Cumin; 1 Tablespoon Chopped Cilantro; 2 cups Shredded Cabbage; 5 Large Radishes, Sliced Into Matchsticks; 2 Tablespoons Apple Cider Vinegar; 2 Tablespoons Sour Cream; 8 Flour Or Corn Tortillas, At Least 5 Inches Across; 6 ounces, fluid Shredded Cheddar Cheese; 2 cups Shredded Leftover Chicken