Preheat oven to 350 F | 175 C. Saute onions in oil, with salt, until translucent and mostly soft. Dress a 10" | 24 cm spring form with the puff pastry. Bake in the oven for 5 minutes. Blend the soy milk, silken tofu, pepper, basil and soy sauce until smooth. Then combine the onions, the soy milk mixture, chives and the couscous. Pour into the spring form. Bake for 30–40 minutes.