Preparation: Wash asparagus; peel tough white outer skin off ends; slice on diagonal in 6 cm sections. Rinse fermented black beans. In bowl, combine and mash black beans and garlic, brown sugar, black soy sauce and chicken stock; stir; reserve for 15 minutes. Stir-Frying: Add two third of oil to hot wok; when oil is very hot, add chicken. Stir-fry for about 3 minutes on high heat or until chicken begins to shrink and firm up. Remove chicken to holding bowl. Reheat wok to high, add remaining oil. When oil is hot, add black bean sauce. Stir-fry for 1 minute. Add asparagus; mix with sauce. Stir sauce with asparagus. When sauce boils, add cooked chicken; toss to combine. Dribble in a little cornstarch paste if needed; cornstarch in chicken marinade might be enough. Toss ingredients until very little liquid remains and is reduced to glaze. Dish is ready when asparagus brightens. If you still have too much liquid, remove ingredients, continue to reduce sauce, then return ingredients to coat them with sauce. Serve in individual portions.