Butter, parsley, lemon juice, and garlic should all be combined and properly mixed in a small stainless steel mixing bowl.
Form the butter mixture described above into a log shape on a piece of wax paper.
For a half hour, chill the log of butter mixture. Slice the chilled butter mixture log into four equal pieces. To serve on top of each steak, keep refrigerated.
In the meantime, season each Delmonico steak with salt and pepper before rubbing it with a little bit of olive oil.
Place each steak in a heavy-duty nonstick skillet that has been preheated over high heat.
Uncovered, sear the steak for 5 minutes on one side, then flip it over and sear for 3 minutes on the other.
For medium doneness, cook for an additional 8 to 10 minutes at a reduced heat, or until the internal temperature reaches 145 degrees Fahrenheit.
Serve slices of the cooled butter mixture on top of each steak.