Soak the pitted dates in hot water for 10 minutes to soften them completely—this will help them blend smoothly into the marinade. While they soak, mince your garlic cloves finely and grate the fresh ginger. In a blender, combine the softened dates, water, coconut aminos, mustard, apple cider vinegar, minced garlic, grated ginger, onion powder, smoked paprika, black pepper, and sea salt. Blend until completely smooth and well combined, then with the blender still running on low speed, slowly drizzle in the olive oil to emulsify the marinade. This creates a silky, balanced sauce with good texture.
Pat the steak pieces completely dry with paper towels to help them marinate more effectively. Score the surface of each piece with shallow crosshatch cuts—this helps the marinade penetrate deeper into the meat. Place the steak in a large bowl and pour the prepared marinade from Step 1 over it, using your hands or tongs to ensure every piece is well coated. Cover and refrigerate for at least 2 hours, but preferably overnight, for deeper flavor development. I find that overnight marinating produces noticeably more tender, flavorful results.
Heat your grill or grill pan to medium-high heat (around 400-450°F). Remove the steak from the marinade, allowing excess liquid to drip off—reserve the remaining marinade for the sauce. Sear the steak pieces for 3-4 minutes per side over the high heat, pressing gently with a spatula to develop a golden crust. Once both sides are nicely browned, reduce the grill heat to medium and continue cooking until your desired doneness is reached (about 4-6 minutes total for medium-rare, depending on thickness).
Transfer the cooked steak to a plate and tent loosely with foil. Let it rest for 5-10 minutes—this allows the juices to redistribute throughout the meat, keeping it tender and juicy. While the steak rests, pour the reserved marinade into a small saucepan and bring it to a boil over medium-high heat. I like to reduce the marinade for 5-10 minutes until it thickens slightly and concentrates in flavor, which creates a more sophisticated sauce consistency.
Slice the rested steak against the grain to maximize tenderness. Plate the sliced steak and drizzle with the reduced sauce from Step 4. Garnish with fresh chopped chives for a bright, aromatic finish. Serve immediately with your choice of sides.