Dear Alton Brown: HELP!

So because I am INSANE, I've decided to have my parents and brother over to my apartment for Easter Dinner. Meaning that I have to cook. And just to knock up the Krazy a few notches, I've decided to make my great grandmother's recipe for leg of lamb. Because heaven forbid I do something simple like ham, which I already know how to make. No, it has to be lamb. Krazy, I tell you.

Anyway, here's her recipe word for word, which I've just secured from my aunt:

"Leg o'Lamb"

Roast of lamb-add onion, celery, parsley, and clove of garlic, together with salt and pepper
Roast until done.
Baste with tomato paste and water.
When near done, add potatoes and noodles.

For real, that's what it says. Yeah, thanks Mom-Mom, no need to get into specifics with that AT ALL. Like, you know, oven temperature. Or how long to cook the thing. Don't give me quantities or anything either. NO, REALLY, IT'S FINE.

I think I need to have a backup ham, just in case.