Preheat the oven to 375Â¡F. Sift together the flour, salt, sugar, and baking powder. Rub in the butter with your fingers.
Mix together the eggs, cream, and mustard. Add this to the dry ingredients. Stir in the grated cheese and the scallions. Mix just until combined. This is the consistency of drop-cookie dough.
Liberally flour the counter and your hands. Pat the dough into a 1-inch-thick rectangle. Cut into 10 triangular scones. Place on a well-greased cookie sheet.
Bake for 20 minutes, or until nicely browned and a cake tester inserted into a scone comes out dry.