Add butter to the Instant Pot. Using the display panel select the SAUTE function.
When butter has melted, add onion to the pot and saute until soft, 3-4 minutes. Add garlic and cook for 1-2 minutes more.
Add Spice Mixture ingredients to the pot and cook for 1 minute or until spices are fragrant.
Add rice and red pepper to the pot and stir well.
Add broth and wine to the pot and deglaze by using a wooden spoon to scrape the brown bits from the bottom of the pot.
Turn the pot off by selecting CANCEL, then secure the lid, making sure the vent is closed.
Using the display panel select the MANUAL or PRESSURE COOK function*. Use the +/- keys and program the Instant Pot for 6 minutes.
When the time is up, quick-release the remaining pressure. Add the shrimp, scallops and frozen peas.
Cook and gently stir until shrimp and scallops are cooked through and most of the liquid has been absorbed, returning to SAUTE mode as needed.
(Optional) Arrange on a paella pan (or other wide, shallow, stovetop-safe pan) and set on the stovetop, uncovered, on medium-high heat until the bottom of the rice forms a crust, about 5 minutes.
Serve family-style sprinkled with cilantro or parsley.