Set the instant pot to saute and add the olive oil.
Add the leeks or onion if using and fry for a couple of minutes.
Add the wine and cook until the alcohol has evaporated (around 2 minutes).
Add the oregano, rosemary, fennel seeds and lentils. Stir together.
Now add the stock, stir and then add the chicken. Put the lid on and set to high pressure for 10 minutes.
Leave under pressure for 5 more minutes and then perform a quick release.
Season to taste and then add the lemon zest, garlic and sundried tomatoes. Stir well to combine.
Now add the spinach and push down into the mixture. Put the lid back on and leave to wilt for around 4 minutes.
Serve with a garnish of fresh basil and enjoy.