Preheat oven to 400°F. Rub chicken breasts with olive oil, salt, pepper, and ranch seasoning.
Place chicken on a baking sheet and roast for 20 to 25 minutes until cooked through.
Let chicken rest for 5 minutes, then shred with two forks.
Melt butter in a large pot over medium heat. Add onion, carrots, and celery; cook for 5 minutes until softened.
Add garlic, bell pepper, and zucchini. Sauté for 2 to 3 minutes until fragrant.
Stir in potatoes, corn, chicken broth, dried thyme, smoked paprika, and chili flakes if using. Bring to a boil.
Reduce heat and simmer for 15 to 20 minutes until potatoes are tender.
Add shredded chicken and half-and-half. Simmer for 5 minutes more.
Adjust salt and pepper to taste. Stir in fresh parsley and chives.
Serve hot with additional herbs if desired.