3cupscooked chickpeas(remove the skins if desired for a smoother texture)
salt to taste(I start with 1 tsp if cooking my chickpeas from scratch, or 1/3 tsp if using canned chickpeas)
Add 1 tbsp of the olive oil to a large, wide skillet over medium heat. When hot, add the onion slices with a pinch of salt and stir well to break them up. Reduce the heat to medium-low so that you just barely hear the onions sizzling. Continue to cook, stirring only occasionally and keeping the onions spread out in the pan, until the onions have reduced significantly in size and darkened deeply (but not burned), about 30 minutes. Set aside.
Add the remaining 1 tbsp of olive oil, lemon juice, tahini and garlic to a food processor and blend until relatively smooth, scraping down the sides if needed. Add half of the cooked chickpeas and half of the caramelized onions, blending to combine. Reserve a few caramelized onions for topping and then add the rest of the onions and chickpeas to the food processor. Blend until smooth, and season to taste with salt and more lemon juice.
Serve topped with the remaining caramelized onions (you can chop them up if you like) and with an extra drizzle of oil, if desired. This caramelized onion hummus is tasty warm and fresh, but it's actually even better after a night in the fridge for the flavors to meld. Leftovers will keep in the fridge for 5-7 days.