Place chicken thighs in a 4 quart casserole with lid, and cover completely with water. Place lid on casserole and bring water to a boil. Cook until chicken is tender, approx 40 minutes. Make sauce while the chicken cooks.
In a mediun saucepan, mix together ketchup, mustard, brown sugar, garlic, honey, steak sauce, lemon juice, and liquid smoke. Season with salt and pepper. Heat to medium and bring to a gentle boil, and simmer for about 10 minutes. Turn off heat and set aside for at least 30 minutes.
When the chicken is cooked, chop or shred meat into small pieces. Place in a pan with the sauce, and cook on low heat for another 15 minutes to let the flavor of the sauce absorb into the chicken. Spoon BBQ'd chicken onto buns, and top with coleslaw.