. Prepare the Steaks:

• Trim any excess fat and silver skin from the steaks.
• Rub with neutral oil and season generously on all sides with kosher salt and freshly cracked black pepper.
• Wrap steaks in plastic wrap and refrigerate for a few hours to enhance seasoning penetration.

2. Make Cowboy Butter:

• In a saucepan over low heat, melt the butter while whisking continually.
• Add lemon juice, lemon zest, garlic, Dijon mustard, and dry seasonings.
• Remove from heat and stir in chives and fresh parsley.
• Season with salt and pepper to taste.
• Set aside a few tablespoons for brushing the steaks while grilling; keep the rest for the slider buns.

3. Cook the Steak:

• Preheat the grill to medium-high heat with an indirect heat zone.
• Remove steaks from the fridge and let them rest at room temperature for 30 minutes.
• Grill steaks over direct heat for 2-3 minutes per side, avoiding charring.
  • If high flames appear, move steaks to indirect heat until flames subside.
• Brush both sides with cowboy butter as they cook.
• After 5-6 minutes total cook time, transfer steaks to indirect heat and continue grilling until the desired internal temperature is reached:
  • 125°F (52°C) for rare
  • 135°F (57°C) for medium-rare
  • 145°F (62°C) for medium
• Remove steaks from the grill, tent with foil, and rest for 10 minutes before slicing.

4. Caramelize the Onions:

• Place a cast iron skillet on the grill over direct heat.
• Melt a few tablespoons of butter in the skillet.
• Add the thinly sliced onions and cook, stirring occasionally, until caramelized (about 15 minutes).

5. Prepare & Assemble Sliders:

• Preheat oven to broil. Line a baking sheet with parchment paper.
• Separate the slider buns and brush the inside with remaining cowboy butter.
• Place havarti cheese on both top and bottom buns.
• Layer the caramelized onions on the bottom buns.
• Add sliced steak to each bottom bun.
• Broil for 1-2 minutes, or until cheese begins to melt.
• Top with slider bun tops, slice, and serve warm!