You can make dishes creamier without using dairy in a variety of ways. First, pureed vegetables work well. Cauliflower, potatoes, winter squash, and broccoli all blend up well to give dishes a creamier texture. You can also use ground and pureed nuts, blended silken tofu, and coconut milk. Start by making the dish with a roux (oil and flour) which will naturally thicken the liquid or you can also add a cornstarch slurry to thicken and sauce and make it creamier.