So long, flavorless chicken dinners.
Bring a large pot of water to a boil for the pasta.
In a small saucepan, bring the broth and porcinis to a simmer over medium heat. Keep the broth at a low simmer until the mushrooms soften, about 10 minutes.
Meanwhile, butterfly the chicken breasts. Starting on the fat side of a chicken breast, cut horizontally across the breast but not all the way through. Open it up like a book. Pound the chicken to about 1/4 inch thick. (For 8 to 12 smaller cutlets, halve the breasts horizontally and then pound the chicken.) Season the chicken with salt and pepper.
Place the flour in a shallow bowl; mix in the sage, granulated garlic, and nutmeg.
Using a slotted spoon, transfer the porcinis to a cutting board and chop. Reserve the mushroom broth.
Dredge the chicken in flour on both sides, shaking off the excess.
In a large skillet, heat 2 tbsp. EVOO, two turns of the pan, over medium to medium-high. Add 2 tbsp. butter to the oil. Add half of the chicken and cook, turning once, until golden, about 6 minutes. Transfer the chicken to a platter and tent with foil to keep warm. Repeat with the remaining chicken, remaining 2 tbsp. EVOO, and 2 tbsp. butter.
Add the remaining 1 tbsp. butter to the skillet. Add the fresh mushrooms and cook, stirring often, until browned, about 5 minutes. Add the shallots, garlic, and thyme. Cook, stirring often, until the shallots soften, about 2 minutes more. Add the marsala and cook, stirring often, until the liquid reduces by half, about 5 minutes; season with salt and pepper. Pour in the porcini broth (avoid any grit that may have settled in the pan). Stir in the cream and chopped porcinis. Let the sauce reduce while you cook the pasta.
Salt the boiling water, add the pasta, and cook 1 minute less than the package directions. Reserve about 1 cup of the pasta cooking water, then drain the pasta.
Spoon half of the sauce over the chicken. In the skillet, toss the rest of the sauce with the pasta, pasta cooking water, and 1 cup cheese until the pasta is coated. Serve the pasta alongside the chicken. Sprinkle everything with parsley and cheese.