In a large mixing bowl stir together the flour, sugar, baking powder, and salt. Make a well in the center. Combine egg, milk and oil. Add egg mixture all at once to flour mixture. Stir just till moistened; batter should be lumpy. Grease muffin cups or line with paper bake cups; fill 2/3 full. Bake in a 400 degree oven for 20 to 25 minutes or till golden. Remove from pans; serve warm. Variations: Banana: Prepare Basic Muffins as above, except decrease milk to 1/2 cup. Stir 1 cup mashed banana into batter. Blueberry: Prepare Basic Muffins as above, except combine 3/4 cup fresh or frozen blueberries, thawed, and 2 tablespoons additional sugar. Add 1 teaspoon finely shredded lemon peel, if desired. Carefully fold into batter.