I like to make square biscuits because there’s no waste, no scrap, no re-rolling and re-cutting (especially because the re-rolled and re-cut round biscuits inevitably wind up tougher than the ones that were cut on the first go round). I use butter, not shortening, and leave the chunks rather large to help yield a flakier biscuit. Don’t over-knead the dough or they wind up chewy (like re-rolled biscuits) because the gluten has been over-developed.
For the gravy, I browned links of spicy sausage, then cut them into small chunks and finished cooking them. Stirred flour into their fat to make a slack roux and whisked in skim milk (no need for anything fattier with so much sausage fat already in the mix) until it reached the right consistency. Simmered a full 30 minutes to cook the starchy, pasty flour texture out, adding additional milk as necessary. I probably used about a quart of milk all told, but that ratio has to do with how much roux I made. If you want to make less gravy, pour off some of the fat before stirring in the flour—or use a lower-fat sausage. I finished the gravy with a touch of fresh thyme.
The gravy would go equally well on French toast, if you don’t feel like making biscuits.
To reheat leftover gravy, heat a small amount of milk in the bottom of a saucepan and whisk the cold gravy into the hot milk in small portions, waiting for one addition to combine and heat before adding the next. This method should allow you to get the gravy hot without breaking the emulsion, which would lead to pools of fat rising to the top and makes for an unsightly sauce.