Bring a large saucepan of salted water to a boil.

Cook the green beans until crisp-tender, about 2 minutes.

Drain the beans and let them cool.

Pat the beans dry with paper towels.

Heat 2 tablespoons of vegetable oil in a large skillet until shimmering.

Add half of the black mustard seeds to the skillet.

When the mustard seeds pop, add half of the jalapeno, ginger, and curry leaves.

Cook over high heat until fragrant, about 30 seconds.

Add half of the green beans to the skillet and toss until hot, about 30 seconds.

Season with salt.

Transfer the green beans to a platter.

Repeat the process with the remaining oil, mustard seeds, jalapeno, ginger, curry leaves, and beans.

Serve hot or at room temperature.