Preheat the oven to 450°. Make the marinade: In a large bowl, combine the sambal, Dijon mustard, and Worcestershire sauce. Whisk in the orange juice. Season the chicken on both sides with salt and add to the marinade.
Heat a cast iron pan large enough to hold both pieces of chicken over high heat. Add the oil and swirl to coat the pan. Add chicken, skin-side down and cook for about 6-7 minutes until the skin is a golden, brown. Turn chicken over and cook for 1-2 minutes. Transfer to a plate and set aside.
To the same pan, add the red pepper, red onion, carrot, celery, cauliflower, and potatoes and toss to combine. Season with salt and freshly ground black pepper.
Return the chicken to the pan on top of the vegetables and place in the oven. Cook about 10 minutes until the chicken is cooked through. Serve right in the pan.