Combine the marinade ingredients in a small blender and blend until smooth. In a medium bowl toss the chicken with the marinade. Refrigerate for at least 2 hours.
Preheat the grill to medium hot. Put the cauliflower on the hot grill. Grill the cauliflower for 2-3 minutes on each side to char. Transfer to a piece of aluminum foil and seal the edges into a packet. Return to the grill. This allows the cauliflower to steam and soften.
Meanwhile, add the chicken to the hot grill. Grill for 7-8 minutes on each side until it registers 160 on a meat thermometer. Cool for 5 minutes and then slice.
Add the dressing ingredients to the small blender. Process until smooth.
To assemble: Divide the spinach between six plates. Top with the julienned basil, sliced chicken breast, and some cauliflower. Add a few slices of kumquat. Drizzle the dressing on top and serve.