Place the mushrooms in a small pot and cover with stock. Bring the stock to a boil and reduce the heat to low simmer to reconstitute the mushrooms.
Season the chicken with salt and pepper on both sides and dredge lightly in flour.
Heat the olive oil in a large Dutch oven over medium-high heat and brown the chicken in two batches until crispy on both sides. To the pan drippings, add the onions, garlic and red pepper and stir to soften. 5-6 minutes. Add the wine or additional chicken stock to deglaze the pan and let it reduce by half. Add the tomatoes and break them up; stir in a few leaves of basil.
Remove the mushrooms from the stock with a slotted spoon; chop them and add them to the sauce. Add all of the mushroom stock except for the last 2 tablespoons or so to prevent any sediment from the mushrooms from getting into the pan. Simmer the sauce for 20-30 minutes at a gentle bubble to thicken a bit.
Add the chicken back to the sauce and simmer for 20-30 minutes more to cook the chicken through. If serving as a main dish and the pasta as a first course, remove the chicken to a warm serving platter and cover to keep warm. If you are serving the pasta as a side dish, this is not necessary.
While the chicken cooks, bring a large pot of water to a boil. Salt the water and cook the pasta to al dente. Reserve about 1/2 cup of the starchy cooking liquid and drain the pasta. Return it to the pot and toss with the starchy cooking water, butter, about one-third of the chicken and mushroom sauce and the parsley. Toss to combine and emulsify. Adjust salt and pepper, to taste; transfer to a warm serving bowl and top with a little more sauce and Pecorino cheese.
Top the chicken with a little extra sauce and pass any remainder at the table in a gravy boat. If you are serving the chicken as a main course separate from the pasta, round out the meal with green beans and or a salad of arugula and red onion.
This is one of many “Yum-o!” recipes – it’s good and good for you. To find out more about Yum-o!, Rachael’s nonprofit organization, visit