Cut the sour cream into your biscuit mix. "Cutting in" is simply incorporating your sour cream, butter or shortening into your dry baking mix without using a mixer. You can use a fork, knife, pastry cutter or the tools God gave you, your fingers. You just want to make sure that each portion of your {wet} ingredient gets coated with the dry mix.
Stir in 1/2 cup 7 Up. The dough will be very soft, don't worry.
Sprinkle additional baking mix on to your counter, about a 1/2 cup seems to work just fine.
Knead and fold dough until coated with your baking mix. Pat dough out, (no rolling pin needed) and cut biscuits using a round biscuit/cookie cutter. Don't have one, no problem, you can certainly use a glass or empty soup can to cut out your biscuits. Where there's a will, there's a way! Improvising is fine.
Melt butter in a 9 inch square pan. I stick my pan and butter in the oven for a few minutes. Just a few though, the butter will burn, so watch it.
Place cut biscuits on top of melted butter and bake for 12-15 minutes or until brown.