Golden Potato, Sausage and Parmesan Hash

Name: Golden Potato, Sausage and Parmesan Hash
Ingredients: 6 oz. smoked sausage (pork, turkey, chicken, etc); 1 yukon potato (large, or 2 small yukon potatoes); 1/2 white onion (small); 3 cups spinach (packed); 1/8 cup parmesan (shaved); 1 tbsp. red wine vinegar (optional); 1/2 tbsp butter (or olive oil); 1 tsp olive oil; salt (to taste); pepper (to taste)