Heat the oil in a large stockpot or Dutch oven. Add the onions and cook until soft. Add garlic and cook for another minute.
Stir in spinach & cauliflower and add broth and red pepper flakes. Bring to a boil and add chicken breasts. Reduce to a simmer and simmer until chicken is cooked, about 20 minutes.
Remove chicken from pot and shred. Lightly mash cauliflower then add chicken back to pot.
Stir in coconut milk, mushrooms & capers, and simmer until heated through before serving.
