It's as simply as cooking them for 2-3 minutes in boiling water and then place them in cold or iced water.
For the sauce:
Finely chop the chili and the green onion, grate the garlic and ginger, then mix all these ingredients with the soy sauce, vinegar, lemon juice, and honey.
Cook the sesame in a frying pan until they start to brown, removing it from the heat before they burn.
In a heated pan, add a drizzle of olive oil and fry the crushed garlic for 2-3 seconds. Add the blanched green beans and cook everything together for 1-2 minutes.