Place the oil, onion, garlic and pepper flakes in a small saucepan. Heat on medium-low heat, then lower the heat once the bulky ingredients start to sizzle slightly. Cook on low heat for 5 minutes until fragrant and the onion becomes translucent. Remove from the heat, add the saffron threads (if using) and infuse for 1 hour. Mince the garlic and set aside.
Drain and rinse the cashews. Place the coconut milk, tofu, cashews, lemon juice, salt and nutritional yeast in a food processor or high-speed blender. Process until smooth. Add the chia seeds and process a few times until slightly thicker. Set aside.
Preheat the oven to 450°F (232°C, or gas mark 8). Place a thin layer of cornmeal on a large baking sheet. Roll out the pizza dough as thin as you can into a rectangle, approximately 11 x 14 inches (28 x 36 cm). Lightly brush the whole surface with infused oil, including the edges. There will be leftovers of the oil, which can be used to stir-fry veggies or to flavor pasta or other grains. Store covered in the refrigerator for up to 1 week.
Top with a layer (not too thick) of cashew preparation. There will be leftovers, which can be used on a future pizza within a week. Store in an airtight container in the refrigerator.
Evenly place the halved squash blossoms on the surface. Top with the minced garlic and with onion slices scooped out from the infused oil with a fork. Bake until golden brown, about 16 minutes. Top with ground pepper, salt and extra Aleppo pepper flakes to taste. Serve immediately.