Generously grease six 2/3-cup popover cups or nine 1/2-cup muffin cups.
In a large bowl with an electric mixer combine milk, flour, oil, and salt and beat mixture on high speed 1 minute. Add eggs 1 at a time, beating 20 seconds after each addition, and beat in chives and pepper.
Divide batter among cups and put in middle of a cold oven. Set oven at 425°F. and bake popovers 35 to 40 minutes, or until puffed and golden brown.
