If using canned chickpeas, place cooked chickpeas and baking soda in a medium saucepan and cover with water. You want 1-2 inches of water above the chickpeas. Bring the mixture to a boil over high heat. If using dry chickpeas, see my note below.
Boil chickpeas, reducing heat if necessary to prevent the pan from overflowing, for about 20 minutes, or until the chickpeas have expanded, the skins are falling off and they're soft, but not mushy. While the chickpeas boil, skim off any foam and/or skins that float to the surface. After 20 minutes, drain the chickpeas in a colander and run under cool water. Set aside.
In a food processor, add lemon juice and tahini. Process for 1 minute. Scrape down the sides of your food processor bowl and add chickpeas, olive oil, garlic, cumin and salt.
Process until smooth (about 2-3 minutes more) gradually adding cold water as desired to thin dip and scraping down sides of the processor bowl as needed. Once the hummus is completely smooth, taste and season as needed.
Transfer to a bowl for serving. Top with a drizzle of olive oil, fresh herbs, za'atar, cayenne pepper and/or paprika. Serve with chopped veggies or pita chips for dipping.
Store any leftovers in the fridge in an airtight container for 4-7 days.