In a small bowl, make the mustard citrus maple dressing. Add and mix all of the dressing ingredients together until the dressing has thickened.
Place the chicken in a frying pan and add 3 Tbs of the dressing on top. Cook over medium heat until the chicken is grilled on both sides.
Slice the grilled chicken into thin slices.
Add the shredded Brussels sprouts, kale, and cabbage to a large bowl. Top with the sliced avocado, cucumber, apples, almonds, and dressing and toss.
Top with sliced chicken and toss again.
