2 T olive oil
1 large sweet onion, chopped
1 lb button or cremini mushrooms, quartered
3 oz Pancetta, chopped
8 garlic cloves, minced
1/2 t ground black pepper
3/4 t dried oregano
3/4 t dried thyme
3 ladles salted pasta cooking water
2 cups arugula, tightly packed
2 T cold unsalted butter, cut into four pieces
1 pound fettuccine
3/4 cup Pecorino Romano, shredded
Prep and assemble all the ingredients nearby. Keep the pancetta and butter in the refrigerator chopped and ready to go.
In a large pan set over medium heat, sauté the onion and mushrooms in the olive oil. Stir infrequently. This lets the onion and mushrooms sit in contact with the pan which encourages browning. Continue to sauté until many pieces are brown and fragrant.
Put water and a good tablespoon of salt into a large pot and bring to a boil for the pasta.
Add the pancetta, garlic, black pepper, oregano, and thyme to the onion mixture shortly before putting the pasta in to boil. Stir frequently.
After the pasta has boiled four minutes, use a ladle and add 3 scoops (about 1/2 cup each) to the onion mix. Stir to deglaze the pan. Add the arugula and butter, stir well. The melting butter will take the water and turn it into a delicious sauce.
Remove an additional ladle of water and reserve in a cup.
Drain the pasta and place in a serving bowl. Toss with the sauce and Pecorino Romano cheese. If the mixture is too dry, add a little of the reserved water.
Serve with a glass of Italian wine, a colorful salad, and a slice of garlic bread.