In a large saucepan, heat the grapeseed oil over medium heat. Add the shallot and garlic and sauté, stirring, for 2 minutes or until soft. Add the edamame and cook, stirring, for 2 minutes. Add the water, tahini, lemon juice, soy sauce, salt, and cumin. Stir and bring to a simmer. Simmer gently for 6 minutes.