Add butter, dill, lemon zest, lemon juice, salt, and pepper to small mixing bowl. Mix well to combine. Using a rubber spatula will help collect all the butter for you.
Cut salmon into portion sizes of your choice. Place dollops of butter compound all around top of salmon pieces. Spread out as much as possible.
Add one cup of water to pressure cooker, along with a few sprigs of thyme and/or dill. Place half of the salmon on standard trivet and insert into pot. Sprinkle with more pepper, if you like. Top salmon pieces with 2 thin slices of lemon.
Place second half of the salmon on a 3-inch trivet and insert into pot. Again, sprinkle with more pepper, if you like. Once again, top salmon pieces with 2 thin slices of lemon.
Lock lid and cook at high pressure for 3 minutes. Once cook time is complete, quick-release pressure. Remove lid and serve immediately.