Place almonds in a small nonstick saute pan. Lightly toast over medium-high heat, about 3 minutes. Add 1 tablespoon tamari and stir until the almonds are coated evenly, about 30 seconds. Transfer to a plate and cool. Chop almonds roughly.
Prepare a large bowl of ice water. In a large pot of boiling salted water, cook beans until crisp-tender, about 8 to 10 minutes.
Drain the beans and transfer to the bowl of ice water. Remove green beans and drain well.
In a large bowl, combine the sesame oil, vinegar, garlic, ginger, and remaining 1 tablespoon of tamari. Add the drained green beans and toss to coat. Garnish with roasted almonds and fresh cilantro, if desired. Serve immediately, while warm.