2 cups all purpose flour
1 1/4 teaspoons salt
2 cups whole milk
4 large eggs

Nonstick vegetable oil spray
1 1/2 cups grated Gruyre cheese (about 6 ounces)

Place one 12-cup muffin pan and one 6-cup muffin pan in oven. Preheat oven to 350F. Whisk flour and salt in medium bowl to blend. Heat milk in heavy small saucepan over medium heat until very warm, about 125F. Whisk eggs in large bowl to blend. Gradually whisk warm milk into eggs. Gradually stir flour mixture into milk mixture just to blend (batter may still be slightly lumpy).

Remove hot muffin pans from oven. Spray pans with nonstick spray. Spoon 1/4 cup batter into each of 16 muffin cups. Top each with 1 1/2 tablespoons cheese. Bake until puffed and deep brown, about 40 minutes. Remove popovers from pan.