What is there in the vicinity of the start for breakfast ? Or will it be a question of buying provisions the night before and eating before leaving ?
There are a few cafes along the B176. Google says that there is a "Windmill Cafe" at the top of Windmill Lane (the road down to the YH from the main road) but no idea about opening times. I'd suggest sussing something out when you are down there for registration.
No experience of them myself though. I've always used the petrol station up the road in Broxbourne/New River as a control on my DIYs up that way. I've definitely passed a few cafes though and always wanted to stop and have a proper breakfast.