Bechamel Sauce:
Melt butter in a skillet over medium heat. Whisk in the flour and continue whisking for 1-2 minutes. Slowly add milk, whisking constantly until smooth, thickened, and bubbly. Whisk in salt, black pepper, and nutmeg.
Add cheese and whisk another 30 seconds. Remove from heat and continue whisking just until cheese is melted and sauce is smooth then set aside to cool before using for pizza. Once cooled, cover and refrigerate up to 5 days.
Shrimp Pizza:
Marinate the shrimp in the chili oil for 20 minutes.
Meanwhile, place the pizza stone in the preheated oven (500ºF. in a regular oven or 850ºF. in an Ooni Pizza Oven) for twenty minutes before cooking the pizza.
Divide the pizza dough into 2 even pieces. Stretch each piece of dough in a circular motion, then lay them both out on a flat surface and flatten out using your hands or a rolling pin. If you have a pizza peel, sprinkle some corn meal on it and place the stretched out dough on the peel.
Once your 2 pizza doughs are flat and ready to be cooked, drizzle the oil and smear the garlic all over the dough. Spread the bechamel all around, and top with zucchini slices and marinated shrimp. Transfer the pizzas into the oven and bake for 12-13 minutes (in a regular oven), or 1 to 2 minutes (in an Ooni Pizza Oven).
Remove pizza from the oven. Drizzle with chili oil, and garnish with fresh basil or green onions. Enjoy!