Place the chicken breasts on a cutting board and gently pound them to an even thickness. Season both sides generously with salt, black pepper, garlic powder, and all-purpose seasoning.
Heat a Dutch oven or large pot over medium heat and add 2 tablespoons of butter. Once melted, add the seasoned chicken breasts.
Cook the chicken for about 4–5 minutes per side, or until golden brown and cooked through. Remove the chicken from the pot and set aside to rest.
Add the remaining 1 tablespoon of butter to the same pot. Add the sliced carrots, celery, and diced onion.
Cook for 3–5 minutes, stirring occasionally, until the vegetables begin to soften. Scrape up any browned bits from the bottom of the pot as the vegetables cook. These browned bits add extra flavor to the soup.
Add the minced garlic and bay leaves. Cook for about 30 seconds, until fragrant.
Pour in the chicken broth and add the chicken bouillon, chili flakes, salt, and black pepper. Stir everything together and bring the broth to a gentle boil. Return the chicken breast and cook for around 15 minutes. Take the chicken breast out.
Add the egg noodles to the pot and cook according to the package directions, or until the noodles are tender.
While the noodles are cooking, shred or slice the cooked chicken into bite-sized pieces.
Once the noodles are cooked, remove the bay leaves and add the shredded chicken back to the soup. Stir and let everything warm through for 1–2 minutes.
Taste the soup and adjust the seasoning as needed. Garnish with fresh or dried parsley and serve hot.