- Preheat the oven to 375°F (190 °C) and grease a standard muffin tin or line with paper liners.
- Whisk the buttermilk, vegetable oil, eggs, sugar and lemon juice (or vinegar) to combine.
- In a separate bowl, stir together the cornmeal, flour, baking powder, baking soda and salt. Add this to the buttermilk mixture and whisk until smooth (batter will be very fluid).
- Stir in the cheddar cheese and scallions and spoon this into the prepared muffin tin. Bake for 15 to 18 minutes, until the muffins are a light golden brown and they spring back when touched.
These muffins are best served within a day of baking.