For added convenience, the flavor-packed "sauce" and topping for this unique pizza may be prepared in advance. Then you can simply assemble and bake when ready to eat!
In a large (12- to 14-inch) skillet, heat 1 tablespoon of the oil over medium-high. Sauté the mushrooms and onions until deeply golden brown in places, about 8 minutes, sprinkling with ¼ teaspoon of salt as they cook and drizzling in the second tablespoon of oil when the skillet starts to appear dry.
In a food processor, process half of sautéed mushrooms/onion mixture (you can eyeball it) with the cream cheese, dried thyme and remaining ½ teaspoon salt. I aim for a mostly smooth mixture that still has some texture. Taste for seasoning, adding another pinch of salt (or even a pinch of red pepper flakes), if desired.
Spread the pureed mixture evenly over the crust. Top with remaining the mushroom mixture and both cheeses. Bake until the crust is golden brown and the cheese is melted, 12-14 minutes. (Tip: to avoid burning the crust, check a few minutes early, as all ovens vary. Also, thin crusts and cauliflower crusts tend to brown more quickly.) If desired, garnish with a tablespoon or two of chopped fresh basil.
Notes
*I like to use an assortment of wild mushrooms (oyster, shitake, maitake, etc.), but anything from cremini to portobellas and regular button mushrooms may be used.A few more things: •The mushroom/onion mixture (through step 3) may be prepared in advance and refrigerated until ready to eat. It will keep for 3-4 days in the refrigerator. •As an option, you could make French bread pizza or mushroom toast. The mushroom mixture would probably taste great with pasta, too. (I’m thinking you could thin the puree with pasta cooking water just enough to be able to toss it into the cooked pasta and then stir in the remaining mushrooms and onions from the skillet, adding a sprinkle of either or both cheeses.) •Those who enjoy the flavor of garlic may add 4 minced cloves in the last minute or so of cooking the mushrooms and onions. •If you start with fresh dough, simply press it into a 12-inch round pizza pan or skillet and pre-bake according to the recipe instructions. •Leftovers taste great and may be gently reheated in the oven or toaster oven.