- Melt the butter in a large shallow saucepan over medium heat. Add the onion and garlic and sauté until the onion is translucent, about 5 minutes
- Add the thyme and rosemary and cook for a minute more. Add the flour and cook, stirring continuously, until the flour is completely incorporated.
- Add the broth, tahini, and liquid aminos and stir until well combined. Cook, stirring frequently, until the gravy is thick and glossy, 5 to 7 minutes. Add the nutritional yeast and remove from the heat.
- Use an immersion blender to blend the gravy until smooth. You can also transfer the gravy to a blender to blend until smooth. Add salt and pepper. Serve immediately. Leftovers will keep in an airtight container in the fridge for 2 to 3 days.