Bring a large pot of water to a boil for pasta.
Heat EVOO in Dutch oven over medium-high heat. Add fennel and beef, and season with salt and pepper. Add sausage and brown and crumble both until caramelized, breaking meats up into small bits. Add rosemary, onions and garlic and cook partially covered about 5-7 minutes, stirring occasionally to soften the onions. Deglaze the pan with a little wine, add stock and tomatoes and simmer 30 minutes.
Cook pasta about 6 minutes, shy of al dente. Toss pasta with sauce and place in casserole. Top with cubes of mozzarella and sprinkle with parm. Bake from room temperature at 400F until cheeses melted and bubbly, 20 minutes. If cooking from refrigerated or frozen, after pasta comes to room temp, cover with foil and bake 30 minutes then uncover to lightly brown, another 10-15 minutes.