If making homemade hummus, place soaked chickpeas in a pot and cover with 3 inches of water. Add baking soda, onion and bay, and bring to boil. Salt water with about 2 teaspoons Kosher salt and keep at low boil, skimming every 40 minutes or until water is mostly absorbed and the chickpeas are very tender. Remove onion and bay, and place beans in a food processor. Add Tahini, lemon juice, garlic and cumin. Process 5 full minutes to form a light and smooth hummus, adjust salt to taste; add bottled water to thin if hummus is too thick.
Whisk up marinade ingredients and toss chicken in to coat. Heat a grill or griddle pan or an outdoor grill over medium-high heat and grill chicken to crispy and brown, 8-10 minutes. Remove meat from heat, let rest and slice.
Add Tahini to food processor with crushed garlic, lemon juice, salt, ½ teaspoon cumin, process, streaming in water to thin as necessary.