Cook veggies: In a large pot over medium heat, heat oil and add sliced bell pepper and mushrooms. Cook until tender and mushrooms begin to brown, about 6 minutes.
Add chicken, paste and sauce: Stir in the fish sauce, red curry paste and shredded chicken. Stir until well combined.
Add liquids and finish: Add chicken broth and coconut milk and bring to a boil. Reduce heat and simmer for two to three minutes while stirring occasionally. Taste soup and add more curry paste (for heat) or fish sauce (for salty flavor) as desired. Remove from heat and serve immediately.
You can store leftovers in a closed container in the fridge for up to 2 days.
We recommend buying a rotisserie chicken that is organic, free-range and free of hormone. Also, check the ingredients to be sure that no sugar is added and only simple seasonings are used. We prefer to shred the chicken into smaller pieces for this recipe.
We use Mae Ploy curry paste since it's one of the best out there. By using a high-quality curry paste (like Mae Ploy), you typically use less paste (unlike Thai Kitchen) since it's more flavorful and spicy. This reduces the amount of carbs, and you don't need to supplement it with additional ingredients like ginger or garlic. If you can't find Mae Ploy, another good brand is Maesri.
Fish sauce adds a salty, umami flavor to the soup. If you don't have on hand, you could swap with soy sauce (although it's not quite the same).
We recommend using Aroy-D coconut milk since it's one of the better coconut milks on the market. We've tried many other brands and weren't as happy with the results.