1. Sauté the vegetables. Set the Instant Pot to Sauté and add the olive oil. Add the onion, carrots, and celery and cook for 5–6 minutes, stirring occasionally, until the onion begins to soften.
2. Stir in the garlic, thyme, rosemary, and turmeric, if using, and cook for 30 seconds. Press Cancel.
3. Pour in a splash of chicken broth and scrape the bottom of the pot with a wooden spoon to loosen any browned bits. Add the remaining broth, Yukon Gold potatoes, chicken, bay leaf, salt, and pepper.
4. Secure the lid and cook on High Pressure for 8 minutes. Let the pressure release naturally for 5 minutes, then carefully vent the remaining pressure.
5. Transfer the chicken to a plate and shred it with two forks. Discard the bay leaf.
6. Use an immersion blender to blend some of the potatoes into the broth, leaving plenty of vegetables intact. Alternatively, scoop out about 2 cups of soup with plenty of potatoes, blend until smooth, and stir it back into the pot.
7. Return the shredded chicken to the pot and stir in the frozen peas and coconut milk. Set the Instant Pot to Sauté on Low and simmer gently for 3–5 minutes, stirring occasionally, until the peas are tender and the soup is heated through.
8. Press Cancel and stir in the fresh parsley and a squeeze of lemon juice, if using. Taste and adjust the salt and pepper. Serve warm with crusty sourdough for dipping.

Storage

1. Refrigerate: Divide leftover soup into shallow, airtight containers and refrigerate within 2 hours. Store for up to 4 days.
2. Freeze: Freeze in airtight, freezer-safe containers for up to 3 months for best quality. Thaw overnight in the refrigerator.
3. Reheat: Warm on the stovetop or in the microwave until the soup reaches 165°F, stirring occasionally. Add a splash of broth if it has thickened.