Place the beans in a bowl, cover with lots of cold water, and leave overnight.

The next day, rinse the beans thoroughly, transfer to a medium saucepan, and toss with the baking soda. Place the pan over high heat and cook the beans, stirring constantly, for three minutes. Add water to nearly fill the pan, and bring it to a boil. Cook the beans until they are tender but not mushy, skimming off and discarding any foam. This could take anywhere from 20 minutes to an hour.

Drain the beans and lightly rinse them, then transfer to a food processor. Add the tahini, lemon juice, garlic, salt and herbs and process until well combined. With the motor running, slowly add the ice water and process until very smooth.

Transfer to a bowl and let sit for at least half an hour before serving.