1. Combine porcini and boiling water in a bowl; cover and let stand 20 minutes or until soft. Drain porcini in a colander lined with a paper towel over a bowl, reserving liquid. Rinse and chop porcini.
2. Heat olive oil in a Dutch oven over medium-high heat. Add onion, 1/2 teaspoon salt, 1/4 teaspoon pepper, and pork; cook 10 minutes or until pork is browned, stirring to crumble pork. Add cremini mushrooms, garlic, remaining 1/4 teaspoon salt, and remaining 1/4 teaspoon pepper; cook 15 minutes or until liquid almost evaporates, stirring occasionally. Add porcini; cook 1 minute. Add tomato paste; cook 2 minutes, stirring constantly. Add reserved porcini liquid and wine; cook 1 minute, scraping pan to loosen browned bits. Add tomatoes; bring to a boil. Reduce heat; simmer 30 minutes, stirring occasionally and breaking up tomatoes as necessary. Stir in milk; cook 2 minutes.
3. Cook pasta according to package directions, adding 1 tablespoon salt to cooking water. Drain. Toss pasta with sauce; top with cheese and parsley.