In a pan over medium heat, add oil. Next add shallot and cook down until fragrant and tender, about 1-2 minutes. Add garlic and saute for another minute.
Add beans to the pan (mostly drained with a small amount of the bean liquid) and saute again. Add vegetable broth, lemon juice and nutritional yeast and stir to combine. Bring to a low simmer, then transfer 1/4 of the mixture into a blender. Blend until smooth and return the mixture to the pan. The result should be a nice, creamy consistency. Alternatively, you can use an immersion blender, just be sure not to blend too much. Or you'll end up with bean mush.
Season the beans with salt and pepper, then remove from heat. When ready to serve, sprinkle with a generous amount of sumac and garnish with scallions or chives. Finish off with a drizzle of olive oil and enjoy with a crusty piece of bread.