1. Bring broth and 1 cup water to a simmer in a small saucepan (do not boil); keep warm over low heat.
2. Heat a Dutch oven over medium-high heat. Add oil; swirl to coat. Add salt and mushrooms to pan; cook for 8 minutes or until browned, stirring occasionally. Remove mushrooms from pan, and set aside.
3. Add sausage to pan, and cook for 3 minutes or until browned, stirring to crumble. Add shallots and garlic; cook 1 minute, stirring constantly. Reduce heat to medium. Add rice; cook for 1 minute, stirring constantly. Stir in wine, and cook until liquid is nearly absorbed, scraping pan to loosen browned bits.
4. Stir in 1 cup broth mixture; cook for 2 minutes or until liquid is nearly absorbed, stirring constantly. Add remaining broth mixture, 1/2 cup at a time, stirring constantly until each portion of broth mixture is absorbed before adding the next (about 30 minutes total). Remove pan from heat. Add mushrooms and spinach; stir until spinach wilts. Top evenly with cheese. Serve immediately.