Throw a two or three slices of multi grain bread, onion, toasted pine nuts, mozzarella, sage and seasoning into a food processor and whiz until a nice consistency.
Using a sharp knife, carefully cut fat away from the meat (not all the way) creating a flap. Stuff with bread mixture, fold fat back over and secure with toothpicks.
Preheat oven 180*C. Heat 1 Tbsp oil in an oven proof fry pan on high. Cook lamb fat side down for 2/3 minutes, searing well. Turn racks and place in oven. Bake for 12/15 minutes for medium. Tranfer to a plate, cover and let rest for 10 mintues.
Meanwhile throw tomatoes on a baking tray, drizzle with olive oil, season and bake until tomatoes are cooked and are starting to split.
Cook spinach for 1/2 minutes in fry pan over med heat until wilted.
Slice lamb and serve with tomatoes and spinach. Mmm yum! Enjoy!