1. Pour garbanzos into a fine strainer set over a bowl to collect liquid; reserve liquid.
2. In a blender, combine garbanzos, 2 tablespoons olive oil, lemon juice, sesame oil, garlic, and 1/3 cup of the reserved garbanzo liquid. Whirl until smooth and creamy. Add salt and pepper to taste, and, if mixture is too stiff, 1 to 2 more tablespoons liquid; hummus should be soft but still stiff enough to hold its shape. Scrape into a shallow serving bowl.
3. Shortly before serving, drizzle with 2 more tablespoons olive oil if desired.