Preheat the oven to 400°F (200°C).

Squeeze excess moisture from the thawed cauliflower rice using a clean dish towel.

In a mixing bowl, combine squeezed cauliflower rice, a large egg, Italian seasoning, salt, pepper, and parmesan cheese.

Press the cauliflower mixture into a 10-inch circle on a parchment-lined pizza pan.

Bake the crust for 35 minutes, or until golden and firm to touch.

Carefully flip the crust and bake for an additional 10 minutes.

In a skillet, heat butter or olive oil, sauté shallot for 5 minutes, then add garlic and mushrooms, cooking until tender.

Spread shredded mozzarella over the crust, add sautéed mushroom mixture, fresh spinach, and more mozzarella.

Bake for 12-15 minutes, until cheese is melted and bubbly.

Let cool for 10 minutes before slicing and serving.