Heat oil in a medium saucepan over medium heat. Saute onion andgarlic until soft and translucent, about 5 minutes. Stir in flour,nutritional yeast, and soy sauce to form a smooth paste. Graduallywhisk in the broth. Season with sage, salt, and pepper. Bring to aboil. Reduce heat, and simmer, stirring constantly, for 8 to 10minutes, or until thickened.