In a mixing bowl, toss the chickens with Essence. In a large heavy pot, heat the olive oil. When the oil is hot, brown the chicken for 6 to 8 minutes on each side. Transfer the chicken to a plate and set aside. 

Add the flour and stir to make a roux. Add the onions and garlic and cook, stirring constantly, wilt and brown the onions, scraping the bottom of the pot to loosen any brown particles, for about 10 minutes. Add the rhubarb, herbs and wine,bring to a simmer. Add the chicken and any juices back to the pan.  Cover and reduce the heat. Stir occasionally and cook for about 45 minutes or until the chicken is tender. Stir in the parsley. Arrange the chicken on a platter and garnish with Essence and parsley and serve with roasted potatoes and green beans.