THE BEST STEAK SANDWICH IN THE HISTORY OF STEAK SANDWICHES

Ingredients

• 2.5 lb Beef Tenderloin (whole piece, trimmed of excess fat and silver skin)
• 2 tbsp Fresh Rosemary (chopped leaves only)
• 2 tbsp Fresh Thyme (chopped leaves only)
• 2 tbsp Fresh Parsley (chopped flat‑leaf parsley)
• 1/2 cup Unsalted Butter (softened, divided for herb butter, garlic butter, and pan‑basting)
• 8 large Garlic Cloves (4 for herb butter, 4 for garlic butter)
• 2 tbsp Olive Oil (extra‑virgin, for herb butter and sautéing onions)
• to taste Kosher Salt (for seasoning steak, onions, and butter mixes)
• to taste Black Pepper (freshly cracked)
• 2 medium Yellow Onion (thinly sliced for caramelization)
• 1/2 cup Mayonnaise (for horseradish aioli and garlic butter)
• 2 tbsp Prepared Horseradish (coarsely grated)
• 1 tbsp Lemon Juice (freshly squeezed)
• 1 tsp Fish Sauce (adds umami to the aioli)
• 8 slices Havarti Cheese (full‑fat, for melting over the steak)
• 2 cups Arugula (peppery leaves, tossed with olive oil and salt)
• 1 large Garlic Bread Loaf (about 12‑inch loaf, sliced horizontally for sandwich)

Instructions

1. Prepare Herbs

   Strip the leaves from rosemary, thyme, and parsley, discard stems, and finely chop the leaves. Measure about 2 Tbsp of each.

   Time: PT10M

2. Make Herb Butter

   In a bowl combine 1/4 cup softened butter, 4 minced garlic cloves, the chopped herbs, 1 Tbsp olive oil, a pinch of salt and pepper. Mix until smooth.

   Time: PT5M

3. Tie the Tenderloin

   Lay the whole tenderloin on a clean board. Cut 5‑6 pieces of butcher’s twine about 12‑inch long. Starting at one end, loop the twine around the meat every 2‑3 inches, creating a double‑loop knot each time. Finish with a tight knot at the tail and trim excess twine.

   Time: PT10M

4. Season the Steak

   Generously coat the tied tenderloin with kosher salt and freshly cracked black pepper on all sides. Pat the herb butter onto the surface, ensuring an even layer.

   Time: PT5M

5. Bring Steak to Room Temperature

   Let the seasoned tenderloin sit uncovered on the counter for about 30 minutes to reach near‑room temperature.

   Time: PT30M

6. Preheat Grill

   Light the grill and set up two zones: direct high heat on one side and indirect low heat on the other. Aim for ~450°F (232°C) on the direct side.

   Time: PT15M

   Temperature: 450°F

7. Sear the Tenderloin

   Place the tenderloin over direct heat. Sear each side for 2‑3 minutes, rotating to get an even crust, total about 10‑12 minutes.

   Time: PT12M

   Temperature: 450°F

8. Finish Cooking Indirectly

   Move the steak to the indirect zone. Close the lid and cook until an instant‑read thermometer registers 125°F (52°C) for medium‑rare, about 15‑18 minutes.

   Time: PT18M

   Temperature: 225°F

9. Rest the Steak

   Transfer the steak to a cutting board, tent loosely with foil, and let rest for 20 minutes.

   Time: PT20M

10. Caramelize Onions

    While the steak rests, heat 1 Tbsp olive oil and 1 Tbsp butter in a skillet over medium heat. Add sliced onions, season with salt, and cook, stirring every few minutes, until deep golden brown and sweet, about 30 minutes. Add a knob of butter in the last 5 minutes for extra richness.

    Time: PT30M

11. Prepare Horseradish Aioli

    In a small bowl combine 1/2 cup mayonnaise, 2 Tbsp prepared horseradish, 1 Tbsp lemon juice, 1 tsp fish sauce, a pinch of salt and pepper. Mix until smooth.

    Time: PT5M

12. Make Garlic‑Herb Butter for Bread

    Blend the remaining 1/4 cup butter with the remaining 4 minced garlic cloves, 1 Tbsp mayonnaise, 1 Tbsp olive oil, 2 Tbsp chopped parsley, salt and pepper to taste. Mix until creamy.

    Time: PT5M

13. Slice the Tenderloin

    Using a sharp knife, slice the rested tenderloin into very thin slices (about 1‑2 mm thick). Keep slices on a warm plate.

    Time: PT5M

14. Toast Garlic Bread

    Slice the garlic loaf horizontally to create a top and bottom half. Spread a generous layer of the garlic‑herb butter on both cut sides. Place on the grill over indirect heat, close lid, and toast until golden and slightly crisp, about 4‑5 minutes per side.

    Time: PT10M

    Temperature: 350°F

15. Assemble the Sandwich

    On the bottom half of the toasted bread, spread a thin layer of horseradish aioli. Layer caramelized onions, then a handful of thin steak slices, top with Havarti cheese slices, a drizzle of any remaining butter mixture, and finish with arugula tossed lightly with olive oil and salt.

    Time: PT5M

16. Final Melt (Optional)

    If you like extra melt, place the assembled sandwich back on the grill for 1‑2 minutes, press lightly, until cheese is gooey.

    Time: PT2M

    Temperature: 350°F

17. Serve

    Cut the sandwich into quarters, serve immediately while hot. Enjoy!

    Time: PT2M

Nutrition Facts

Calories

800

Protein

45 g

Carbohydrates

45 g

Fat

45 g

Fiber

3 g