Sear chicken in a skillet or pan over medium heat to brown all over (or in your 6-quart instant pot on 'sear/sauté' setting. Transfer chicken to your slow cooker or instant pot bowl. Add the diced onion, carrots, red peppers (capsicum), corn, creamed corn, potatoes, chicken broth and garlic powder. Stir and cover with lid; cook on slow cooker high setting for 3-4 hours or low setting 6-8 hours. For Instant Pot, set to Pressure Cook on Soup setting for 30 minutes. When potatoes are fork tender and chicken is falling apart (45 minutes before the end of cooking time), stir in the cream. Whisk together the cornstarch and milk and mix it into the soup. Cover and allow to thicken on high heat setting. Use a potato masher to make the chowder thicker. Stir in salt and pepper to taste; add in the cheese; top with the bacon; garnish with fresh chives and serve.