Whiz the onions, spices and the meat in a food processor until well chopped together. Pulse in the eggs and the breadcrumbs and season generously with salt and pepper. Tip on to a work surface and shape into 8 balls.
Strip the leaves off the bottom of the rosemary sticks, leaving the leaves on the tops (reserve the stripped leaves). Cut the ends of the rosemary sticks at an angle and push a stick through each ball of meat, leaving the tufty, leafy bit sticking out.
Chop the tomatoes in half and squeeze out and discard most of the seeds. Chop a little more and spread out with the garlic and the chopped-up extra rosemary leaves in 1 or 2 small roasting trays. Season and drizzle with just a little olive oil.
Place a baking rack over each tray of tomatoes and lay the meatloaf balls on top. Put the tray in the oven for 30 minutes or until the meat is cooked and crisp on the outside. Cover the rosemary sticks with foil if they start to look too brown. (The tomatoes taste fantastic with all the meaty juices from the meatloaf stirred in.)
Serve 1 meatloaf per person with some tomatoes and juices from the tray. Sprinkle with fresh basil just before serving.