Roast Lamb with Pistou

Preparation

1. For pistou:

   Step 1

   With processor running, drop garlic through feed tube and chop finely. Scrape down sides of work bowl. Add basil; process until finely chopped. With processor running, add oil through feed tube and process until mixture is pureed. Mix in cheese. Season with salt and pepper. Transfer to small bowl.

2. For lamb:

   Step 2

   Preheat oven to 450°F. Form slit in lamb with tip of sharp knife. Insert garlic sliver and some chopped basil into slit. Repeat all over lamb. Place lamb on rack in roasting pan. Brush generously with oil. Sprinkle with salt and generous amount of pepper. Roast 20 minutes. Reduce oven temperature to 375°F. Continue roasting until thermometer inserted into thickest part of lamb registers 130°F, basting occasionally with drippings, about 1 hour longer. Cool 1 hour. (Can be made 1 day ahead. Cover pistou and lamb separately; chill. Bring to room temperature before serving.)

3. Step 3

   Slice tomatoes; place around edge of platter. Slide basil leaves between tomato slices. Slice lamb; arrange on platter. Drizzle pistou over lamb and tomatoes.