Gather and prepare all your ingredients: dice carrots and celery, chop onion and garlic, and shred any leftover cooked chicken.
Heat olive oil in a large heavy-bottomed pot over medium heat until shimmering and fragrant.
Add chopped onion and minced garlic to the pot, sauté until fragrant and translucent, about 3 minutes. You should hear a gentle sizzle and see the onions turn soft and slightly golden.
Toss in the diced carrots and celery, cook for another 5 minutes, stirring occasionally until the vegetables soften and release a sweet, earthy aroma.
Pour in the chicken broth and bring the mixture to a gentle simmer. Let it cook for about 10 minutes, allowing flavors to meld and the broth to become fragrant.
Stir in the shredded cooked chicken and add the egg noodles. Cook until the noodles are tender and al dente, about 8 minutes, stirring occasionally to prevent sticking.
Taste the soup and season with salt and pepper as needed. Squeeze in fresh lemon juice to brighten the flavors and stir to combine.
Turn off the heat and let the soup rest for a few minutes. Garnish with chopped parsley or dill for a fresh, vibrant finish.
Serve the hot soup in bowls, ensuring each has a good mix of vegetables, noodles, and chicken. Enjoy the comforting aroma and wholesome flavors!