1. Prepare the Chicken: If desired, parboil the chicken pieces in boiling water for 5-7 minutes to remove impurities and excess fat. Drain well and rinse under cold water. This step is optional but recommended for a cleaner stew.

2. Make the Sauce: In a large bowl, combine gochujang, gochugaru, soy sauce, minced garlic, minced ginger, sugar, sesame oil, and black pepper. Mix well until a smooth paste forms.

3. Combine Ingredients: Place the prepared chicken pieces, potatoes, carrots, and chopped onion into a large pot or Dutch oven. Pour the prepared sauce over the chicken and vegetables. Add the water or chicken broth.

4. Cook on Stovetop: Bring the mixture to a boil over medium-high heat. Once boiling, reduce the heat to medium-low, cover the pot, and simmer for 30-40 minutes, or until the chicken is cooked through and tender, and the potatoes and carrots are soft.

5. Thicken the Sauce: Uncover the pot and increase the heat to medium-high. Let it simmer for another 10-15 minutes, stirring occasionally, until the sauce has thickened slightly to your desired consistency.

6. Serve: Garnish with chopped green onions. Serve hot with steamed white rice and kimchi or other Korean side dishes.

7. Slow Cooker Adaptation: To cook in a slow cooker, combine all ingredients (chicken, vegetables, sauce, and liquid) in the slow cooker pot. Cook on low for 4-6 hours or on high for 2-3 hours, until the chicken is fall-off-the-bone tender and vegetables are soft. A slight thickening of the sauce may occur naturally, or you can uncover for the last 30 minutes to reduce it slightly.