In a heavy large enamel cast iron pot heat the olive oil the garlic over medium heat. Once the garlic is brown, but not burned, remove and discard.
Add the onions, parsley, and carrots, and mix well. When the onions are translucent, add the sausage meat and pancetta, and separate them well with the back of a wooden spoon. Add the tomato paste and mix well.
Cook the meats until all the liquid is evaporated.
Add the bay leaves, red wine, chopped porcini mushrooms, Chinese mushrooms half of the strained mushrooms liquid. Mix well.
Add the tomatoes, salt, and pepper. Mix well, lower the heat to simmer, cover, and cook stirring occasionally for 1 hour to 1 ½ hours.
Taste and adjust the salt and pepper to your liking. Add more wine if too dry. Cook uncovered for another 30 minutes.
Remove the bay leaves before serving.
TO MAKE POLENTA
Bring the water to a boil. Gradually add the polenta and whisk vigorously to prevent lumps from forming. Change to a wooden spoon and continue to stir until it becomes thicker, around 6 minutes.
Remove the polenta from the heat and place on a plate or platter. Add the mushrooms ragu over it. Sprinkle a very generous amount of parmesan cheese over it.Serve hot and immediately.