It looks to me like a chestnut tree. If there are some nearby, may have blown over, or buried by a squirrel.

If evergreen, maybe a Holly, a Holly Oak, or an evergreen species of Prunus. It looks like it's in a tough spot, which may account for the slow growth, though the oak, at least, spends its first few years growing roots.

my first thought was one of the sweet chestnuts.

Could easily be--chestnuts don't grow where I am. Hmpph! All of the pictures that I can find are either horsechestnuts, or have blunter lobes. Still a possibility--seedlings of any tree have incredibly variable foliage, only occasionally matching the adult's.

Mahonia aquifolium? I saw some growing wild today and the seedlings were just like this.

Could be, though I would expect the leaves to be compound by this time. That does suggest a another possibility, though--one of the evergreen Berberis species.

Thank you for all your replies everyone.

I think we have finally identified it as a Berberis Julianae.

I also think it is a kind of Mahonia still quite young So the leaves will darken as it matures.

Well, Kaiglen, remember that Mahonias have pinnately compound leaves, usually from an early age, while this seedling has simple leaves, even after 2 years.