Dice the chicken breast into bite-sized pieces. Add the coconut oil to the bottom of a large soup pot over medium-high heat and then add the chicken. Saute the chicken until it is brown on all sides (it doesn't need to be completely done yet).
While chicken is cooking, remove the seeds from the bell pepper and cut it into strips. Chop the zucchini into half circles. Quarter or half the mushrooms.
Add the garlic, ginger, red curry paste, bell pepper, zucchini, and mushrooms in with the chicken. Cook until chicken is cooked through and veggies are tender crisp to your liking.
Add the broth, coconut milk, salt, lime juice, and red pepper flakes. You can adjust the heat with the red pepper flakes or more curry paste. We used just 1/4 teaspoon of red pepper flakes and it was pretty mild.
Turn the heat down to low and allow the soup to simmer for at least 15 minutes before serving. Top with chopped green onions and cilantro for garnish.
NOTE: We used Thai Kitchen brand red curry paste. If you can't get that, make sure to watch the ingredients.
NOTE: You can totally make this vegetarian or even vegan by replacing the chicken broth with vegetable broth and leaving the chicken out. You might want to increase the veggies. I would suggest another zucchini and more mushrooms to replace the chicken as the red pepper is already quite prevalent.