In a large skillet, heat the oil over medium heat. Add the onions and cook gently to sweat for about 2 minutes. Do not let the onions caramelize. Add the garlic and rosemary and cook about 1 minute, or until garlic is lightly browned.
Add the veal and pork and cook, smashing the meat apart with a wooden spoon, to keep it from clumping together. Cook for about 2 minutes and season with salt and pepper to taste. Add the mushrooms and continue to cook about 4 minutes, evaporating any liquid and caramelizing the meat.
Add the porcini juice to the meat and cook for 1 minute to evaporate. Add the veal stock and cook for 2 minutes. Add the marinara and the wine. Reduce the heat and simmer for 3 to 4 minutes. Stir in the parsley.
Toss 2 tablespoons of the Parmesan into the sauce to help it bind. Add some reserved pasta water, as necessary, if the sauce appears too dry. Top with the remaining Parmesan.
Heat the olive oil in a large non-reactive pot over moderate heat. Add the onion and saute until translucent, about 8 minutes. Add the parsley and garlic and cook briefly to release their fragrance. Add the tomatoes, basil and salt. Simmer briskly until reduced to a sauce like consistency, stirring occasionally so nothing sticks to the bottom of the pot. The timing will depend on the ripeness and meatiness of your tomatoes and the size of your pot. If the sauce thickens too much before the flavors have developed, add a little water and continue cooking.
Taste and adjust the seasoning. If the sauce tastes too acidic, add the baking soda and cook for 5 more minutes. If it needs a touch of sweetness, add the sugar and cook for 5 more minutes. Remove the basil stem before serving.