Whisk together 5 tablespoons of the vinegar, 3 tablespoons of the canola oil, 2 teaspoons of the molasses and a pinch of salt and pepper in a large mixing bowl. Add the beans, celery stalks and diced onion. Gently stir to combine. Season with additional salt and pepper if needed. Cover with plastic wrap and refrigerate until ready to serve.
Heat 3 more tablespoons of the canola oil in a large saucepan over medium-high heat. Add the chopped onion and cook until softened and lightly browned, about 5 minutes, stirring occasionally. Add the garlic and cook until softened, about 2 minutes, stirring constantly. Stir in the cocktail sauce and the remaining molasses and vinegar. Bring to a boil, and then reduce to a simmer. Simmer, uncovered, until slightly thickened, about 5 minutes. Turn off the heat and pour half of the barbeque sauce into a small bowl for basting. Keep the remaining barbeque sauce warm until ready to serve.
Heat an outdoor grill or large cast-iron grill pan over medium heat. Brush the chicken with the remaining oil and sprinkle liberally with salt and pepper. Grill the chicken until charred on both sides but not cooked all the way through, 15 to 20 minutes. Baste the chicken liberally with the reserved barbeque sauce and continue cooking until the internal temperature is 160 degrees F, about 5 more minutes. Transfer the chicken to a large plate and allow to rest at least 5 minutes before serving.
Serve the grilled chicken legs with the remaining warm barbeque sauce and chilled bean salad. Garnish the bean salad with the sliced celery leaves.
From Food Network Kitchens