Heat oven to 400F. Grease the bottom of 12 medium muffin cups (alternatively, skip greasing them and use cupcake liners to make cleanup a breeze). In large mixing bowl, beat egg. Add milk and oil then mix. Add flour, sugar, baking powder and salt and mix just until flour is moistened (batter should still be lumpy). Fold in blueberries. Divide batter up into 12 muffin cups. Bake 20 to 25 minutes or until golden brown.