Sear garlic in sauce pan with a little oil. Add tomatoes and herbs, cook on low for 1 hr. Slice polenta log into ½" disks; rub disks with lemon then spread thin layer of bread crumbs on each side and place on oiled baking sheet. Bake at 350˚F for 30 mins, flip half way through.
When done, transfer polenta disks onto oven-safe plates. Slice Mozerella into 1.5" disks. Put a hearty scoop or two of tomato sauce over polenta and arrange Mozzarella slices on top. Bake at 250˚ until cheese is melted.
Rinse mussels with cool water and place in steamer. Pour beer, water and juice of leftover lemon over mussels into steamer. Steam over high heat. When mussels are open, they are done.
When cheese is looking delicious, remove plates form oven, arrange mussels around polenta and serve steaming hot!