Like much ground hamburger, principally kosher (8)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

First letter (principally) of H [amburger] + ALLOWED (kosher). I think the definition is as in “hallowed ground”, but I’m not convinced by it. Surely only a small proportion of ground (not much of it) is hallowed? Otherwise it wouldn’t be special.