Leg of lamb meal advice?

So I’ve decided to have leg of lamb for Christmas dinner. There might be 11 or 12 people, or maybe only 9, I think. I have some ideas, and would love to hear suggestions, and I have some more specific questions.

With the lamb, I’m wondering which half of the leg I should use. I don’t think I need the whole leg, so maybe the upper half? I don’t think I want to do much other than to roast it in garlic and rosemary. But if you have some other idea about that, please share.

I know for sure I want to have pan-roasted fingerling potatoes. I love the texture of those potatoes and they go well with lamb gravy.

I also want some kind of mint sauce—maybe a fresh mint infused with rasberry vinegar?

So what else? I have this idea of a kind of latke made of celeriac, and a sweet potato (I have orange, purple and white available). But then, that’s a lot of last minute frying work. For some reason the idea of spanakopita came to mind—some kind of spinach and dough thing—quiche-like? But isn’t spanakopita a huge labor drain?

Do you have vegetable suggestions? This is a family that is not into nightshades or much cruciferous stuff.

Go wild, jellies!