Melt the butter in a large stock pot over medium-high heat, then cook the celery and carrots for 3 minutes. The vegetables should begin to soften around the edges and smell lightly sweet, not brown.

Stir in the minced garlic and cook for 30 seconds. As soon as the garlic smells fragrant, move on so it does not brown and turn sharp.

Pour in the chicken stock and add the rosemary, thyme, crushed red pepper flakes, salt, and black pepper. Taste the broth before adding extra salt, then stir in Better Than Bouillon chicken flavor or bouillon granules if it needs more savory depth.

Bring the seasoned broth to a boil and add the homemade egg noodles or dry pasta. Keep the broth at a steady boil until the noodles are al dente, with a tender outside and a slight firmness in the center.

Take the pot off the heat as soon as store-bought noodles are barely tender. Residual heat continues cooking the pasta, so stopping early helps prevent a mushy texture.

Stir in the rotisserie chicken and taste once more before adjusting the seasonings. The chicken should warm through while remaining moist and easy to pull apart with a spoon.