Add 1 cup of water to the bottom of a 6-quart instant pot (1 1/2 cups for 8-quart instant pot).

Place the trivet in the pot, with the "feet" touching the bottom and the handles pointing up and resting on the sides of the pot.

Pat the salmon fillets dry on both sides and arrange them in a single layer on top of the trivet.

Sprinkle salt, pepper, and herbs over the fillets and lay a lemon slice on top of each fillet.

Close and seal the instant pot. Set it to manual (high) pressure for 1 minute for fresh fillets or 4 minutes for frozen fillets.

Wait for the pressure to build and the cook time to start. Once the cook time finishes, immediately vent to release the pressure. When the pin drops, carefully open the instant pot lid.

Check the salmon's doneness by inserting an instant-read thermometer at the thickest part. It should register 135 to 140 degrees F. If the salmon is at 145 degrees F or more, use a trivet to carefully remove it from the instant pot and serve it immediately. If it's between 135 and 140, let it sit in the pot, uncovered, for 5 minutes to come to temperature, then serve. If it's less than 135 degrees F, recover the instant pot and let the salmon sit a few minutes more to continue cooking in the warm pot.

Serve hot with a pinch of salt and pepper to taste.