Spaghetti Squash Alfredo with Portobello Mushrooms

Name: Spaghetti Squash Alfredo with Portobello Mushrooms
Ingredients: 4 Portobello Mushrooms; 1 cup Raw Cashews (preferably Soaked Overnight In Water And Drained); 1 Tablespoon Nutritional Yeast; 1 Tablespoon Vegan Butter (I Use Earth Balance); ¾ cups Almond Or Soy Milk; 1 Tablespoon Tahini; 1 teaspoon Dijon Mustard; 3 cloves Garlic, Minced; 1 Tablespoon Lemon Juice; ½ teaspoons Sea Salt; ½ teaspoons Red Pepper Flakes; 2 cups Baby Spinach; 1 Medium Spaghetti Squash; 1 teaspoon Olive Oil; Salt And Pepper, to taste