Lightly coat a large non-stick skillet with oil and bring it to medium heat. When hot, dribble another half dollar-size spot of oil in the skillet. (The more oil the crispier the taco shell.) Place a tortilla over the spot of oil and 'twirl' it a bit to coat it thoroughly.

Place a large spoonful (2 tablespoons) of ground beef across the center of the tortilla. Sprinkle almost as much cheese on top of the meat. Then place a generous portion of lettuce behind the meat and cheese, toward you, and fold in half. Heat through. Repeat for each taco.

(Taco-folding tip: Slide the front edge of the tortilla up the side of the skillet about an inch, bring the opposite edge to meet it, and hold it closed for a few moments with a spatula. Gravity keeps the contents from spilling out.)

In a large skillet, 2 or more tacos can be heating while a third is being assembled. More on a griddle. Transfer hot tacos to a warming tray or serving platter; reheat, if necessary, before serving. Serve with Guacamole (below), and/or salsa and sour cream.

Makes 2 dozen tacos.