Set your Instant Pot to sauté and heat olive oil.
Remove sausage from casing and brown until cooked through.
Add in onion, celery, carrots, and garlic and sauté until fragrant.
Add zucchini and sauté another minute.
Pour in lentils and chicken stock and give everything a good stir.
Place lid on your IP and lock, setting for 12 minutes on manual.
After cook time, do a quick release.
Remove lid after the Instant Pot beeps and unlocks.
Stir in spinach leaves until they wilt.
Add in fresh basil to taste and salt and crushed red pepper, if desired.
Serve with Pecorino Romano (measured in your blue container) and enjoy!
