In a food processor or blender, combine the beans, miso, tahini, cumin, garlic and lemon juice. Process or blend on high speed until the mixture starts to come together.
With the machine running on low speed, slowly add the cold water, 1 tablespoon at a time, until the mixture looks creamy but not too loose. Taste and season with salt and pepper.
To serve, spoon the hummus into a shallow bowl and drizzle with a little olive oil, a sprinkle of black pepper and the chives. Serve with pita, breadsticks or chips and assorted vegetables for dipping.