In a 10-inch skillet over medium-high heat, add butter. Once it’s melted, add mushrooms and a pinch of salt. Sauté for 8 minutes or until they just start to brown. Add shallots and sauté for 5 minutes; the onion should be translucent and softened. Add garlic and sauté for 1 minute. Add the spinach to the pan with a pinch of salt, stirring gently until it starts to wilt. I added it in two batches to make mixing easier. Sauté for 5 minutes or until it’s cooked down and wilted. Add the vegetable stock and pasta, stirring until well combined. Bring to a boil, then simmer, covered, over medium-low heat for 14 minutes, stirring occasionally. Add cheese, parsley, basil, and salt and pepper to taste. Mix well, then cook over medium-high heat until the sauce is thick and creamy, about 3 minutes. Stir in lemon juice and serve while warm.