In a large heavy bottom saucepan, heat 5 tablespoons olive oil over low heat. Add the ½ cup finely diced yellow onion and cook for about 10 minutes until they are translucent and soft.
Stir in the ¼ cup sweet white rice flour and cook, stirring, for about 3 minutes, until the roux thickens. Whisk in the 2 cups vegetable broth and 1 tablespoon tamari sauce, then add salt and pepper to taste.
Cook the gravy over medium heat until thick and bubbling.
May be made in advance and heated to serve; you may need to thin a bit with water or broth.
Notes
Be careful when cooking the roux. You absolutely do NOT want to burn the oil-flour mixture. I recommend stirring the roux continuously over medium-low heat to cook it without overcooking, and watching it carefully. If you do end up burning it, discard and start again.
Use vegan butter. I am so happy using olive oil here, but for a richer-tasting vegan gravy you can use your choice of non-dairy butter or margarine.
Sweet white rice flour substitute. You can try ¼ cup of cornstarch in place of the sweet white rice flour.
Make it a mushroom gravy. Add 1 cup of chopped mushrooms to the pan when you are cooking the onions for a mushroom-flavored vegan gluten free gravy.
Add minced garlic. Likewise, you can add 2 cloves of minced garlic to the onions to add extra depth of flavor.
Make ahead: My secret Thanksgiving prep weapon is to make gravy ahead of time so that I have one less thing to deal with when I'm cooking on Thanksgiving day. Here's how to do it: Make the gravy according the recipe card, then cool to room temperature. Transfer the gravy to an airtight container and store it in the fridge for up to 3 days. Tip: Use a glass container so that you can reheat directly from the storage container. The gravy will thicken as it rests in the fridge. When you reheat it, whisk in a little water or broth until it reaches your desired consistency again.