To make cream sauce: In saucepan over medium heat, add oil or butter. Saute onions until translucent then add garlic and mushrooms. Cook until mushrooms release moisture and begin to caramelize.
Stir in picked thyme and cook 1 minute to release oils.
Add heavy cream and bring to gentle simmer. Let it reduce slightly, 5-7 minutes.
In small bowl, mix cornstarch and water to make slurry. Slowly whisk into simmering cream sauce until it reaches desired consistency.
Remove from heat and stir in truffle oil. Taste and adjust seasoning with salt and pepper.
To prepare pizza: Preheat Current Model P Smart Pizza Oven to 850 F. While oven heats up, roll dough out to 8-12 inches and add desired amount of cream sauce.
Top with mozzarella, mushrooms, spinach and sausage, as desired. Once oven is hot, cook pizza 2 minutes until bubbly.