Preheat oven to 400 degrees F (200 degrees C).
In a large bowl, mix together the flour, baking powder, baking soda, salt, thyme, and sugar. Cut in the butter with a pastry cutter or crumble with your hands until mixture looks like coarse crumbs. Stir in buttermilk and knead on a floured surface for two minutes.
Form the dough into a roughly 7×7 inch square and cut into 12 pieces, but don’t separate them. Bake in preheated oven for 15-20 minutes, or until knife inserted into center biscuit comes out clean.
While the biscuits are baking, start the gravy by browning the sausage. Remove the sausage from the pan with a slotted spoon, but leave the grease. If it’s more than two tablespoons, don’t add the butter. If it’s less, add the butter to the grease over medium-high heat.
Once the butter has melted, add the flour. Cook for about a minute, stirring constantly. Add the milk and cook for another 3-5 minutes, or until the mixture starts to thicken.
Add the sausage and plenty of black pepper. Cook for another two minutes, then taste. Add more pepper to taste. Remove from heat. Add a little more milk if the gravy gets too thick.
Split two biscuits in half and arrange on a plate. Top with gravy and a sunny side up egg, if desired.