Place dried mushrooms in small pot and cover with water or chicken stock. Bring to a boil then reduce heat to low and steep.
Heat a heavy pot over medium to medium-high heat with 2 turns of the pan EVOO. When hot, add butter and melt into oil then add portabellas, onions, carrots, celery, garlic, and bay leaf. Saut until tender, 15 minutes, then season with salt, pepper and nutmeg, stir in tomato paste and cook 1 minute. Stir in wine and reduce 2 minutes to evaporate. Add crushed or pureed tomatoes and stir. Reduce heat.
Remove dried mushrooms from steeping liquid and chop. Stir into sauce. Add steeping liquid, reserving the last few spoonfuls in pot as any grit on the mushrooms will have settled there. Stir in milk. Simmer over low heat 20-30 minutes to thicken.
Bring a large pot of water to a boil, salt water and cook pasta to al dente. Drain pasta and toss with sauce. Serve in shallow bowls, topped with parsley and Pecorino cheese.