Add the olive oil to a large pot over medium heat, and season the chicken thighs with salt and pepper.
Once the pot is hot, pan sear the thighs in the pot for 3 minutes on one side, then flip and cook for another 2-3 minutes, until cooked through.
Pull the chicken thighs out of the pot and transfer them to a cutting board.
Add the carrots, celery, onion, and garlic to the pot, and cook for about 7-10 minutes, until the vegetables are softened and slightly browned on the outside.
While the vegetables are cooking, slice the chicken thighs.
Add the sliced chicken thighs to the pot with the vegetables. Stir in the chicken broth and bay leaves. Cover the pot and bring to a simmer, then add the noodles and cook according to the package instructions.
Once the noodles are cooked through, stir in the lemon juice, taste and add salt and pepper if needed, then garnish with parsley and serve!