Start by combining the Greek yogurt, whole grain mustard, grated garlic, and hot sauce in a small ramekin. Season with a pinch of sea salt, cover, and let it chill in the fridge. This allows the garlic to mellow and the flavors to fuse.

Dry your beef cubes thoroughly with paper towels. In a cast-iron skillet, heat the grapeseed oil until it begins to shimmer. Add the beef in a single layer—don’t crowd the pan! Season generously with the cracked pepper and salt as they sizzle.

Let the meat sit undisturbed for 2 minutes to develop a dark, caramelized exterior. Give the pan a shake or use tongs to flip the pieces, cooking for another 2 minutes until browned on all sides.

Reduce your burner to medium. Toss in the butter and minced garlic. As the butter foams, use a large spoon to continuously pour the hot garlic-butter over the steak bites for about 60 seconds. This "basting" technique ensures the garlic flavors penetrate the meat without burning the cloves.

Transfer the beef tips to a platter and pour the remaining pan butter over the top. Scatter fresh chives over the dish and serve immediately with the chilled mustard cream.