Serves 4 1 can (28 ounces) diced tomatoes in juice 1 tablespoon olive oil 3/4 pound sweet or hot Italian sausage, casings removed 1 small onion, finely chopped Coarse salt and ground pepper 1 cup Arborio rice 1/2 cup dry white wine 1 bunch flat-leaf spinach (10 to 14 ounces), washed well, tough stems removed, chopped (about 7 cups) 1/2 cup grated Parmesan cheese, plus more for serving (optional) 2 tablespoons butter In a small saucepan, combine tomatoes (with their juice) and 3 cups water. Bring just to a simmer; keep warm over low heat. In a medium saucepan, heat oil over medium. Add sausage and onion; season with salt and pepper. Cook, breaking up sausage with a spoon, until sausage is opaque and onion has softened, 3 to 5 minutes. Add rice; cook, stirring until well coated, 1 to 2 minutes. Add wine; cook, stirring until absorbed, about 1 minute. Add about 2 cups hot tomato mixture to rice; simmer over medium-low heat, stirring occasionally, until absorbe...