Preheat oven to 400. Cut the top off the head of garlic so it still remains in tact. Drizzle a little olive oil over top, wrap in foil and place in the oven for 35-40 minutes. Remove and squeeze out the garlic, it should be like a paste. Combine yogurt and 1 1/2 cups wheat flour in a stand mixer with the dough attachment and stir until combined well (alternatively, you can stir by hand). Roll dough into a circle about 1/4 inch thick. Prick with fork and bake at 400 for 10 minutes. Over medium heat, whisk 4 tbsp olive oil and 4 tbsp flour until it bubbles. Add warmed almond milk a little at a time, constantly whisking to blend. It will thicken after each addition. When all milk is added, add roasted garlic, salt, pepper and nutmeg,continue to whisk until the mixture is well blended and thickens up, about 5 minutes. Spread 1 cup white sauce over pizza crust. Add chicken, spinach, and cheese. Bake for 10 minutes, serve immediately.