Preheat the oven 375 degrees. In a saute pan, heat the olive oil. When the pan is smoking hot, saute the celery, onions, carrots, shallots and garlic. Saute the vegetables for 1 to 2 minutes or until the vegetables are wilted. Add the ground meats and saute until the meat is brown, about 4 to 5 minutes. Strain the fat off the meat. Turn the meat into a saucepan. Deglaze the pan with the red wine. Add the stock and milk. Season with salt and pepper. Bring up to a boil and reduce to a simmer. Simmer for 1 hour and add the crushed red tomatoes. Continue simmering for 45 minutes or until the mixture resembles a thick, meaty stew. Grease a 3 quart baking dish. Slice the polenta into 1-inch slices. Spoon a small amount of the ragu over the bottom of the dish. Arrange the polenta over the ragu. Top the polenta with the ragu and sprinkle with the cheese. Repeat the procedure until all the polenta is used. Spread any remaining ragu on top and sprinkle with remaining cheese. Bake for 1 hour covered and the last 5 minutes uncovered. Spoon the mixture into a shallow bowl. Garnish with cheese and green onions.