As it happens, once in awhile, Passover and Easter are cheek by jowl this year. (Passover begins the evening of Friday, March 30; Easter is Sunday, April 1.) By tradition, both religious holidays share a couple common foods, lamb and the egg. Passover Seder plates hold both (in the form of a shank bone, commonly lamb, and a boiled egg) and many Christian families roast a leg of lamb for their Easter dinner after the Easter egg hunt is over. Today’s recipe is for a roast leg of lamb, a preparation that my brother, Marc, and I have made many dozens of times for dinner on Sundays over the years, including some Easter Sundays. Marc has lived overseas for just under 30 years and many of those Sunday dinners took place in France.