Preparation:

Step 1: Sauté the Vegetables

1. Heat the vegetable oil in a large nonstick pan over medium-low heat.
2. Add the diced bell pepper and cook, stirring frequently, until softened (about 3-4 minutes).
3. Add the scallions and cook for another 1-2 minutes.
4. Stir in the minced garlic and cook for 30 seconds, making sure not to brown it, as that can make it bitter.

Step 2: Prepare the Curry Base

1. Add the coconut milk, red curry paste, fish sauce, and dark brown sugar to the pan.
2. Whisk everything together and bring the mixture to a gentle boil.
3. Reduce the heat and let it simmer uncovered for about 2 minutes, allowing the flavors to meld and the sauce to slightly thicken.

Step 3: Cook the Chicken

1. Add the thinly sliced chicken to the simmering curry sauce.
2. Stir occasionally and let it simmer gently for about 5-8 minutes, or until the chicken is fully cooked and tender.
3. Avoid letting the sauce boil vigorously, as this can toughen the chicken.

Step 4: Finish and Serve

1. Stir in the lime juice, chopped cilantro, and finely chopped peanuts.
2. Taste and adjust seasoning with more lime juice if needed.
3. Serve hot with steamed jasmine rice and lime wedges on the side.