1 1/2 links fresh lean turkey sausages (about 6 oz), casings removed
1 1/2 cups whole milk
8 oz whole-wheat spaghetti
1/4 tsp red pepper flakes, or to taste
6 oz spinach leaves (about 6 packed cups)
1 tbsp fresh lemon zest
1/2 tsp ground black pepper
1 1/2 oz Parmesan cheese, grated
Mist a large pot or saucepan with cooking spray and heat to medium-high. Add sausage and cook, stirring and crumbling with a spatula, until no longer pink, about 3 minutes. Transfer to a small bowl and set aside.
To same pot, add 2 cups water and milk and bring to a boil on medium-high. (TIP: Watch carefully and stir from time to time, as milk has a tendency to boil over.) Add spaghetti and pepper flakes. When liquid returns to a boil, reduce heat to medium-low, cover and simmer, stirring frequently, until spaghetti is just short of al dente, 11 to 15 minutes.
Stir in spinach and simmer, uncovered, until spinach is wilted, most of the liquid has absorbed and spaghetti is al dente, 2 to 4 minutes. Add lemon zest, black pepper and sausage and stir until heated through, 30 seconds to 1 minute. Divide among plates and top evenly with cheese.