Separate the head of garlic into cloved, peel the cloves, and slice cloves into slices and ⅛ inch thick.
Using a sharp paring knife or similar, cut small slits in the lamb. As you make each slit, leave the knife in the slit and press in a sliver of garlic.
Continue making and filling slits every 1 ½ inches or so over than entire leg of lamb.
Crush coriander seeds in mortar and pestle or by placing in plastic bag and pounding gently with rolling pin, rubber mallet, or similar.
Combine salt, black pepper, crushed coriander seeds, and minced garlic.
Mix in a drizzle of olive oil, mixing and slowly adding oil until mixture just holds together.
Rub mixture over entire leg of lamb.
Let lamb sit at least an hour before roasting. If the lamb is going to sit more than an hour, refrigerate it.
Roast lamb
Preheat oven to 425° F.
Place lamb in roasting pan or on baking sheet, resting on a rack.
Roast lamb for 30 minute, then turn heat down to 350°.
When you turn heat down, drizzle some of the wine over the lamb, then baste occasionally, adding wine if the pan dries out.
After 1 hour, check internal temperature with an instant-read thermometer. Check temperature every 10 minutes, until temperature reaches 130° for medium rare (125° for very rare). Total cooking time should be between 1 ½ and 1 ¾ hours.