I did not cook my ghee long enough and it doesn’t have the browned toasty flavor. Can I re-cook with another stick of butter to get the toasty butter flavor
The toasty flavor, as you point out, comes from browning the milk solids before they are removed. I don't see any downside to adding a new stick of butter and repeating the process. Depending on how much clarified butter you created initially, it might not be as toasty, but you should get some flavor. In either case, you are not impacting the functionality of the ghee. Ghee and clarified butter essentially behave the same way. Removing the solids allow them to be used with higher heat, eliminating the burning of the solids during cooking.