Melt the butter in a heavy bottomed saucepan over medium heat. Add the onions and cook uncovered, stirring every 3-4 minutes until softened and caramelized. This will take about 30 minutes. Turn down the heat to medium low if the onions seem to be browning too quickly. Set aside to cool slightly.
Add the caramelized onions (reserve 1 tablespoon for topping), tahini, red wine vinegar, olive oil, 1 tablespoon of water, garlic, salt and pepper to the bowl of a food processor.
Blend for about a minute until combined and creamy. Add the chickpeas and process for 1 minute. Stop and scrape down the edges of the bowl.
Repeat 2-3 additional times until smooth and creamy. If the hummus seems too thick, add water 1 tablespoon at a time and pulse until desired consistency is reached.
Taste and add additional salt and pepper as needed.
Enjoy topped with the reserved caramelized onions and a drizzle of olive oil.
Notes
LeftoversStore leftover hummus in an airtight container in the refrigerator for up to 4 days or freeze for up to 3 months.