Spray a 12” skillet with cooking spray, and heat over medium-high heat. Add sausage and mushrooms, and cook and crumble meat until mostly cooked through and mushrooms are nicely browned.

Stir in rice, and pour in tomatoes (undrained) and chicken broth. Bring to a fast simmer.

Reduce heat to low, and cover. Cook 20 minutes, stirring at least twice during cooking, until liquid is mostly absorbed.

Reduce heat to the lowest setting, and remove lid. Stir in spinach and about half the cheese until the spinach leaves are wilted and cheese is melted. Sprinkle remaining cheese evenly over the skillet. Cover until cheese is melted (1-2 minutes), then serve.