Vegan Onion Cheese Sauce

2 tbsp canola oil
1 onion, diced
2 tbsp flour
1 1/2 cups vegetable broth
1 cup soy milk
1/2 cup nutritional yeast
1/2 tsp salt
1/2 tsp pepper
1/4 tsp dry mustard

Over medium heat, simmer onion in oil or vegan butter until tender. Reduce heat to low and coat with flour. Over high heat, add water or vegetable stock, stirring constantly until thickened. Add soy milk, nutritional yeast, and spices stirring until thickened. For more onion flavor, add onion powder.