PASTA WITH LENTILS AND ARUGULA

Steps:

• Heat oil in a large skillet over medium-low heat. Add onions and 1/2 teaspoon salt; cover, and cook until onions wilt, about 20 minutes. Uncover; raise heat to medium. Cook, stirring often, until onions are dark brown, 20 to 25 minutes more.
• Add 1/4 cup water; stir to loosen any browned bits from pan. Stir in tomatoes; remove from heat.
• Meanwhile, in a medium saucepan, cover lentils with water by 1 inch. Bring to a simmer. Cover; cook until lentils are tender but still holding their shape, 15 to 20 minutes. Drain; stir into onion mixture. Season with salt and pepper.
• Cook pasta in a pot of salted water until al dente. Reserve 1 cup pasta water; drain pasta, and return to pot.
• Add lentil mixture, arugula, cheese, and reserved pasta water; toss. Season with salt and pepper. Serve with more cheese, if desired.