Boil a small pot of water. Cook edamame 3–4 minutes, drain, then rinse under cold water.
Add edamame, garlic, lemon juice, tahini, cumin, salt, and pepper to a food processor. Pulse until finely chopped.
With the motor running, stream in olive oil and 2 tbsp water. Blend until creamy, adding more water as needed.
Scrape the bowl. Fold in cilantro and green onions, or pulse once or twice to keep flecks visible.
Taste and adjust seasoning. Swirl into a bowl and finish with a pinch of red pepper flakes.