Heat oven to 450°. Generously grease 6-cup popover pan with shortening. Place pan in oven 5 minutes to heat.
Meanwhile, place milk in 1-cup microwavable measuring cup. Microwave uncovered on High 40 to 50 seconds or until warm. Beat eggs slightly in medium bowl with fork or wire whisk. Stir in flour, milk and salt with fork or wire whisk just until smooth (do not overbeat). Fill popover pan cups half full. Bake 20 minutes.
Reduce oven temperature to 350°. Bake 15 to 20 minutes longer or until deep golden brown. Immediately remove from pan. Serve warm.