Step 1 Heat the oven to 375 degrees.
Step 2 In a large bowl, sift the flour, sugar, baking powder, baking soda and a pinch of salt together. Add the margarine and mix together by hand until mixture is slightly dry and crumbly, and the margarine is reduced to pea-sized crumbs. Mix in the cheddar cheese and green onions. Add the buttermilk and knead. Turn the mixture out onto a floured cutting board or work surface and knead a few more times. Roll the dough to about an inch thick and form into a rectangle. Cut into 12 equal squares. Place on lined baking sheet, slightly spaced apart.
Step 3Bake until the top appears golden brown, cracked and firm, 10 to 12 minutes.