Foods
Gorse flowers are edible and can be used in salads, tea and to make a non-grape-based fruit wine.
As fodder, gorse is high in protein and may be used as feed for livestock, particularly in winter when other greenstuff is not available. Traditionally it was used as fodder for cattle, being made palatable either by "bruising" (crushing) with hand-held mallets, or grinding to a moss-like consistency with hand- or water-driven mills, or being finely chopped and mixed with straw chaff. Gorse is also eaten as forage by some livestock, such as feral ponies, which may eat little else in winter. Ponies may also eat the thinner stems of burnt gorse.

Fuel
Gorse bushes are highly flammable, and in many areas bundles of gorse were used to fire traditional bread ovens.

Wikipedia

I don't know of it's nutritional makeup no sorry Dave, maybe someone else could answer? Probably a good question for the Wild Food section in our forum.