In a medium bowl, combine chicken and fish sauce to marinate. Set aside.
Prepare Panang Curry Paste
Heat a small pan on medium heat, then dry toast coriander and cumin seeds for about a minute or until fragrant.
In a mortar and pestle, grind toasted coriander seeds and cumin seeds to a fine powder. Add peanuts and grind until a fine powder. Add in garlic cloves and crush until you almost have a paste. Add in red curry paste. Check the ingredients list on the red curry paste to see if it includes shrimp paste. If it doesn’t, mix in shrimp paste as well and set aside.
Cook Curry:
In a large wok or pan on medium high heat, add 1/2 cup of coconut milk. Reduce until it’s a very thick cream, about 3 - 4 minutes. Mix in Panang paste and cook until the oil starts to release from the mixture. Add in sugar and kaffir leaves. Cook for a few seconds, then add in onions to cook until they start to soften.
Add in chicken and saute until it’s 90% cooked. Pour in the rest of the coconut milk and cook for another 2 - 3 minutes, until the chicken is fully cooked. Stir in bell peppers and cook for another 30 seconds to 1 minute until soft. Turn off heat, taste, and add salt if needed. Serve over fresh hot rice.
Notes
Fish Sauce: Fish sauce may smell pungent to first-time users, but don't worry! Once it's cooked, it blends beautifully with the rest of the ingredients and adds a depth of flavor along with its saltiness.
Unsalted Peanuts: There's already plenty of salt from the shrimp paste, fish sauce, and curry paste, so we don't want to make the curry too salty with the peanuts. Remember, we can always add more salt, but you can't take it back once it's added!
Dried Kaffir Leaves: This one ingredient gives the dish its signature flavor, so I don't recommend skipping it! You may be able to find it at local Asian markets or on Amazon.
Curry Paste: Depending on the brand, some red curry pastes already include shrimp paste as an ingredient. If that's the case, you can omit the shrimp paste from the Panang curry paste.