Bring a colander pot of salted water to a boil. Drop the green beans into the boiling water and blanch for 2 minutes. Remove the beans and run colander under cold water long enough to cool completely, about 15 seconds. Drain and place on paper towels or a kitchen towel to dry.
Drain and rinse beans in the colander and leave to dry with paper towel. When dry, mix in a large bowl with the green beans, celery, and parsley. Divide into 4 lunch containers.
In Pyrex measuring cup with a pouring spout, whisk together the olive oil, apple cider vinegar, garlic, mustard, honey, and salt. Pour into 4 small containers.
