Cut chicken breasts into bite-sized cubes and set aside. In a large Dutch oven or soup pot, melt butter over medium heat, then whisk in flour to create a roux, stirring constantly for 2 minutes until it turns light golden and smells nutty.

Add diced onion, celery, and minced garlic to the roux, cooking for 3-4 minutes until vegetables become fragrant and onions turn translucent. This aromatic base creates the foundation for your entire creamy chicken chowder that tastes deeply satisfying.

Pour in chicken broth slowly while whisking to prevent lumps from forming in your roux. Add bay leaves, thyme, salt, and pepper, then bring the mixture to a rolling boil over medium-high heat for 2 minutes.

Add diced potatoes and carrots to the broth, then reduce heat to medium and simmer for 8-10 minutes until vegetables begin softening. The potatoes should be fork-tender but not falling apart when the next ingredient joins the pot.

Stir in corn kernels and diced bell pepper, then add cubed chicken breast. Simmer for 5-7 minutes until chicken cooks through completely and internal temperature reaches 165°F when measured at the thickest point.

Reduce heat to low and stir in heavy cream, folding gently to incorporate without creating air bubbles. Heat through for 2-3 minutes without boiling, as boiling cream can cause separation and affect the soup's silky texture.

Taste and adjust seasonings as needed, adding more salt or pepper to your preference. Remove bay leaves before serving this loaded comfort soup to avoid any unpleasant bites of concentrated herb flavor.