In a large pot, melt the butter or oil over medium-high heat. Add the onion, carrots, and celery and cook until tender, about 5 to 7 minutes. Add the garlic and cook for one minute. Stir in the bay leaves and thyme.: As the butter or olive oil warms you will hear a soft sizzle when the vegetables hit the pan, and the kitchen will begin to smell sweet and aromatic as the onion , carrots , and celery release their moisture. The goal here is translucence and tenderness, not browning, so keep the heat steady and stir occasionally. When the vegetables soften they contribute sugars and body to the final broth, which deepens the overall flavor. If you rush this step by turning the heat too high you risk caramelizing or burning the onion , which will add a bitter note. A common mistake is letting the garlic sit too long; add it last so it becomes fragrant in about a minute without turning bitter. The bay leaves and thyme should be stirred in so they bloom in the warm fat, releasing subtle herbal aromatics that will infuse the broth.
Pour in the chicken broth and bring to a boil. Add the noodles and simmer for 5 to 6 minutes or until tender, but not all the way cooked. You don’t want them to get mushy.: When the chicken broth hits the pot you will see it shimmer and slowly gather into a gentle boil. That rolling motion helps distribute heat evenly so the noodles cook uniformly. Add the egg noodles and listen for a quieter, steady simmer which indicates the starches are releasing. The noodles should be slightly underdone at this point because they will finish cooking later with the chicken . Textural control is important, since overcooked noodles will become limp and soggy. If your pot goes from simmer to a vigorous boil, lower the heat; too much agitation can break delicate noodles and cloud the broth. A common oversight is skipping the brief noodle pre cook, leading to a mushy final texture.
Stir in the shredded cooked chicken and simmer for 2 to 3 minutes. If the soup is too thick for your liking, you can add more broth.: Once you fold in the shredded chicken the aroma will gain meaty depth, and the pieces will warm through, releasing juices into the broth. Simmer briefly so the chicken becomes tender and melds with the noodles without overcooking. This short finish helps the meat stay moist and prevents it from drying out. If you find the soup is thicker than you prefer, pour in more chicken broth a little at a time until you reach the desired consistency. Avoid adding cold liquid straight from the fridge if you can, because it will drop the temperature drastically and interrupt the gentle simmer; instead use room temperature or warm liquid.
Stir in the lemon juice, parsley, and season with salt and pepper, to taste.: Adding the fresh lemon juice at the end brightens the entire pot and cuts through the savory richness. The chopped Italian parsley will add a green, herbaceous flash and a fresh aroma. After these additions, taste and adjust with kosher salt and freshly ground black pepper , since seasoning right at the end ensures you do not over salt early when the broth is concentrated. A typical error is over seasoning before the flavors have had time to meld; always taste after the finishers are in place.
Remove the bay leaves and ladle the soup into bowls. Serve warm.: Before serving, fish out the bay leaves so no one encounters their papery texture. As you ladle, notice the steam rising, the fragrant mix of herbs and citrus, and the way the noodles cradle the shredded chicken . Serve it warm so the contrasts between bright lemon and savory broth are most pronounced. One small trap is letting the soup sit too long uncovered, which can lead to a thin skin forming on top; keep it covered if you are not serving immediately.