Linguine with Onions

Cook pasta and reserve 1/2 cup water. Add olive to a large pan over medium heat. Once oil is hot add onions. Cook over medium low heat for approx 30 minutes stirring frequently. Boil water and cook pasta. Reserve 1/2 cup water. Add garlic to softened onions, and seasonwith salt and cracked pepper. Add mushrooms and 2 tbsp butter. Cook until mushrooms start to soften, add cherry tomatoes and beans. Cook until heated through and add spinach, sprouts, pasta and remaining 2 tbsp butter. Season again and toss well. Serve with cheese, more sprouts and chili flakes.