Combine seasoned salt, 1 tablespoon black pepper, onion and garlic powder, oregano, paprika and chili powder in a 1-gallon sealable plastic bag. Mix thoroughly and then add 1 piece of meat, shake it around in the bag, remove it and repeat with the second piece of meat. When both pieces are done, return them to the bag, and let marinate for 24 to 48 hours in refrigerator. Remove meat from refrigerator at least 20 minutes, prior to grilling.
In a medium-sized bowl, combine the sour cream, mayonnaise, lemon juice, horseradish, garlic and sea salt and pepper. Mix thoroughly and place into refrigerator for at least 4 hours.
Set grill or large grilling pan to high heat. Cook meat for 20 minutes or until desired temperature. Remove from heat, cover and let rest for 5 to 10 minutes. Best served medium-rare.
Slice cooked and rested steaks paper thin using either a knife or counter-top deli-slicer. Place 4-ounces of meat on a slice of toasted rye and spread on sour cream horseradish.