In a large skillet or wok, heat the oil over medium heat. Add the sliced onion, green bell pepper, and red bell pepper. Sauté for about 5 minutes, or until the vegetables are tender and the onions are translucent.
Increase the heat to medium-high and add the chicken pieces to the skillet. Cook for about 5-7 minutes, stirring occasionally, until the chicken is no longer pink and starts to brown slightly.
Add the minced garlic, grated ginger, and Panang curry paste to the chicken mixture. Stir well to coat the chicken and vegetables with the paste, cooking for another 2-3 minutes until fragrant.
Reduce the heat to medium and pour in the coconut milk. Stir in the peanut butter until well combined. Bring the mixture to a gentle simmer.
Stir in the light brown sugar, fish sauce, and lime juice. Taste and adjust the seasoning as needed. If you want a thicker curry, mix the cornstarch with a tablespoon of water to create a slurry, then add it to the skillet, stirring until the sauce thickens.
Once the curry has thickened to your liking, remove it from the heat and stir in the chopped basil leaves. They will wilt slightly, releasing their aromatic scent.
Serve the Panang Curry hot over a bed of your favorite rice. Enjoy the creamy, flavorful dish that will transport you straight to Thailand with every bite!