- 1 teaspoon kosher salt, plus more for the pot
- 3 tablespoons extra-virgin olive oil
- 1 medium onion, sliced
- 8 ounces mixed mushrooms, sliced (button, cremini, shiitake, chanterelle, oyster)
- 8 ounces chicken livers, trimmed of fat and sinew, chopped into ½-inch pieces
- Pinch of crushed red pepper flakes
- 1 cup canned whole Italian plum tomatoes, preferably San Marzano, run through a food mill
- 1 cup frozen peas
- 1 pound spaghetti
- 2 tablespoons chopped fresh Italian parsley
- 1 cup freshly grated Grana Padano
Bring a large pot of salted water to a boil for the pasta. To a large skillet over medium-high heat, add 3 tablespoons of the olive oil. When the oil is hot, add the mushrooms and onion. Cover, and cook until the mushrooms release their liquid, about 4 minutes. Uncover and increase the heat to boil away the liquid and brown the mushrooms, stirring only occasionally so they have a chance to brown.
Add the chicken livers, and season with the salt and crushed red pepper flakes. Cook, stirring occasionally, until the livers are browned all over, about 3 minutes. Add the tomatoes and ½ cup pasta water, bring to a simmer, and add the peas. Cook until the peas are tender, about 5 minutes.
Meanwhile, cook the pasta in the boiling water. When the sauce is ready and the pasta is al dente, remove the pasta with tongs and transfer directly to the simmering sauce. Add the parsley, and toss to coat the pasta with the sauce, adding a splash of pasta water if it seems dry. Remove the skillet from the heat, sprinkle with the grated cheese, toss, and serve.