Turn on Pressure Cooker to Sauté or Browning setting, then add 2 T olive oil
Add chicken and season with salt and pepper to taste (about 1/2 t each). Sear for 2-3 minutes - do not cook through.
Add pasta, water, 1/2 t salt, plus 1 T butter, cut in small pieces
Stir lightly. Close lid, and close vent knob - on Instant pot, turn vent knob to “Sealing”.
Set cook time to 4 minutes on High Pressure - for Instant Pot, press Manual and adjust cook time with “+/-“ buttons to 4 minutes.
When cook time is complete, quickly release pressure (QPR) and remove lid.
Press cancel or off on your pressure cooker. Turn on sauté or browning function.
Add pesto and stir.
Add spinach, stir and allow to wilt, 1-2 minutes.
Turn cooker OFF and Serve immediately. Garnish with parmesan cheese, cracked pepper and/or crushed red pepper, if desired.