I added my LME an started my boil. Stupid me forgot to add the buttering hops and the inititial boil right after adding the LME. I boiled for about 20 min before I realized. Should I start my boil time over when I added the hops?
That's what I would do. I assume you're doing a partial boil so you're going to be adding top up water anyway, so you don't need to account for evaporation losses.