The roast lamb dinner that many eat on Easter Sunday goes back earlier than Easter to the first Passover of the Jewish people. The sacrificial lamb was roasted and eaten, together with unleavened bread and bitter herbs (see Passover Seder) in hopes that the angel of God would pass over their homes and bring no harm. As Hebrews converted to Christianity, they naturally brought along their traditions with them. The Christians often refer to Jesus as The Lamb of God. Thus, the traditions merged.
“We eat this every year for Easter. It is a family favorite. I normally cook half of a leg. If you cook a whole leg of lamb, double the recipe. You need to start this recipe at least 24 hours before cooking. It needs to marinade at least overnight.”
Mix yogurt, 4 sprigs of rosemary, 1/2 bunch of parsley, smashed garlic, and zest of 1 1/2 lemons in a large bowl. Place the leg of lamb in the yogurt mixture and stir to coat. Cover and refrigerate for 24 to 48 hours.
The next day, preheat an oven to 400 degrees F (200 degrees C). Spread onions on the bottom of a roasting pan. Remove lamb from the marinade, rinse and pat dry. Set aside.
Place olive oil, salt, pepper, 4 sprigs of rosemary, 1/2 bunch of parsley, 1/2 head of garlic, and zest of 1 1/2 lemons in a food processor. Process until the mixture becomes a smooth paste. Rub leg of lamb with the paste, and place on top of the onions in the roasting pan.
Bake in the preheated oven for 20 minutes, then reduce the temperature to 325 degrees F (165 degrees C). Continue baking until desired doneness, 40 to 50 minutes for medium. An instant-read thermometer inserted into the center should read at least 160 degrees F (70 degrees C).