Combine tahini and lemon juice in a food processor, processing for 1 minute, then scraping the sides and processing for another 30 seconds.
Add the olive oil, minced garlic, and cumin to the whipped tahini and lemon juice mixture. Process for 30 seconds, scrape sides and bottom of bowl then process another 30 seconds.
Open can of chickpeas, drain liquid then rinse well with water. Add half of the chickpeas to the food processor then process for 1 minute. Scrape sides and bottom of bowl, add remaining chickpeas and process for 1 to 2 minutes or until thick and quite smooth.
If the hummus is too thick or chunky, slowly add 2 to 3 tablespoons of water until the consistency is perfect.