01 - Pat steak cubes dry with paper towels. Season evenly with kosher salt and black pepper.
02 - Heat olive oil in a large skillet over high heat.
03 - Add steak cubes in a single layer, working in batches if necessary. Sear for 1-2 minutes per side until browned and medium-rare to medium inside. Remove steak bites to a plate and tent with foil.
04 - Reduce heat to medium. In the same skillet, add butter and let it melt. Add minced garlic and sauté for 30 seconds until fragrant.
05 - Stir in Dijon mustard, lemon juice, smoked paprika, red pepper flakes, parsley, chives, dill, sea salt, and black pepper. Simmer for 1 minute until sauce is cohesive.
06 - Return steak bites to the skillet, tossing to coat thoroughly in cowboy butter sauce. Serve immediately, spooning extra sauce over the steak bites.