Peel and chop the carrots and celery into bite-sized pieces, and roughly chop the onion. Mince the garlic and grate the ginger for a fragrant base.
Set your Instant Pot to sauté mode. Add a splash of oil, then toss in the chopped onion, garlic, and ginger. Cook, stirring often, until the mixture is fragrant and the onion turns translucent, about 2-3 minutes. The kitchen will fill with a warm, spicy aroma.
Add the chopped carrots and celery to the pot, stirring to combine with the aromatic mixture. Cook for another minute until the vegetables start to soften slightly.
Place the chicken breasts into the pot, then pour in the chicken broth. Lightly smash the lemongrass stalk and add it to the pot for a citrusy aroma. Stir to distribute everything evenly.
Secure the lid on the Instant Pot, ensuring the valve is sealed. Set to high pressure and cook for 15 minutes. During this time, the chicken will become tender and the flavors will meld beautifully.
Once cooking is complete, carefully perform a quick release to release the pressure. Open the lid and check that the chicken is cooked through and tender enough to shred easily with a fork.
Remove the chicken breasts from the pot and shred them with two forks. Return the shredded chicken to the soup and stir well, allowing it to soak up the flavorful broth.
Taste the broth and add salt if needed. Discard the lemongrass stalk and serve the soup hot, garnished with fresh herbs or a squeeze of lime if desired. Enjoy the bright, comforting flavors with tender chicken and crisp vegetables.
