Get a large pot of water heating to a rolling boil while you toast the sesame seeds in a dry skillet over medium heat for 2 minutes, giving the pan gentle shakes to prevent burning. You'll smell their nutty aroma when they're ready.
⏱ 2 min
Transfer the warm sesame seeds to a mortar and pestle and grind them into a coarse paste, leaving some seeds partially whole for textural interest. The mixture should be fragrant and slightly oily but not completely smooth.
Stir the ground sesame seeds together with the soy sauce and sugar until well combined. The sugar will dissolve slightly, creating a thick, glossy dressing. Set this aside while you prepare the beans.
Working with a small handful of green beans at a time, snap off both ends and pull away any tough strings that come loose. Line up the trimmed beans on your cutting board—you'll cut them after blanching.
Add the salt to your boiling water, then drop in the green beans. Cook for 4-5 minutes until they turn bright emerald green and yield slightly to a fork but still have some snap. Don't overcook—they'll continue softening slightly as they cool.
⏱ 5 min
Immediately drain the beans in a colander and rinse them under cold running water to halt the cooking process. Shake the colander well and let them drain thoroughly—excess water will dilute your dressing.
Line up the cooled beans and cut them crosswise into neat 2-inch pieces. Uniform pieces not only look better but ensure every bite gets the right ratio of bean to dressing.
While the beans are still slightly warm, toss them gently with the sesame dressing until each piece is well coated. Serve immediately at room temperature, or chill for up to 2 hours for a refreshing cold salad.