Any ideas what this may be?

[BewareTheBeardedDragon]

Intriguing looking tiny leaves emerging - any ideas what they may be? Finger in second pic for scale.

With those fleshy cotyledons with marked veins I’d be expecting a cucumber or squash

My first thought was that it's a euphorbia.

I can't see how any cucurbit seeds could have got to this spot. Euphorbia is a possibility, there are two nearby. What about hollyhock?

Doesn’t look like euphorbia, it usually spreads through creeping roots.
I’d go with the veg option. Could they be courgettes or broad beans?

I guess I'll wait and see what the true leaves begin to look like. I will be scratching my head if they do turn out to be squash or some such but perhaps I used some homemade compost here and forgot about it, there will certainly be such seeds in that. Interesting!