From The Happy Herbivore
Steam green beans until cooked but still slightly crisp and deep green in color. Once the green beans are cooked, whisk cornstarch with broth and Dijon mustard, to taste.
Pour Dijon mixture into a skillet and add remaining ingredients, except green beans, salt and pepper.
Bring to a boil, then reduce to low and allow it to thicken into a glaze. Taste, adding more Dijon, lemon or onion flakes as desired. Add salt and pepper to taste, toss with green beans and serve.