Sausage, Tomato, and Arugula Fettuccine

1 9-ounce package fettuccine or linguine
2 tablespoons olive oil
1 onion, chopped
6 ounces Italian turkey sausage (i actually doubled this)
2 teaspoons minced garlic (though I love garlic and would have double to tripled this)
1 pint cherry tomatoes
1/4 tsp salt
1/4 tsp freshly ground black pepper
3 cups baby arugula leaves
parmesan to your heart's desire
Preparation

• 1. Cook pasta according to package directions, omitting salt and fat. Drain in a colander over a bowl, reserving 2/3 cup cooking liquid.
• 2. While pasta cooks, heat oil in a large skillet over medium-high heat. Add onions and cook for 3-5 minutes, until "glassy". Remove casings from sausage. Break sausage into bite-sized pieces and add to pan; cook 3 minutes or until browned, stirring frequently to crumble. Add garlic; cook 30 seconds, stirring constantly. Add tomatoes and pepper; cover and cook 2 minutes. Mash tomatoes with the back of a wooden spoon to break them up. Cover pan; reduce heat to low, and cook 3 minutes. Remove pan from heat. Add pasta, reserved 2/3 cup cooking liquid, and arugula; toss well. Sprinkle with pecorino Romano.