In a skillet over medium heat, add the chopped leek and sauté for 5-7 minutes until softened and slightly caramelized. Remove from heat and let cool.

In a bowl, combine the softened butter, sautéed leek, smoked paprika, salt, and pepper. Mix until well combined.

Transfer the butter mixture onto a piece of parchment paper. Roll it into a log shape, twisting the ends to seal. Refrigerate until firm.

In a dry skillet over medium heat, add the mustard seeds. Toast them for 2-3 minutes until they start to pop and become fragrant. Remove from heat and let cool.

Season the ribeye steaks generously with salt and black pepper on both sides.

In a bowl, combine the toasted mustard seeds, minced garlic, thyme, rosemary, and olive oil. Mix to create a paste.

Rub the mustard seed mixture evenly over the surface of the ribeye steaks.

Preheat a grill or skillet over high heat. Add the butter and let it melt.

Add the ribeye steaks and sear for about 4-5 minutes on each side for medium-rare, or until your desired doneness is reached. Use a meat thermometer for accuracy (130°F for medium-rare).

Remove the steaks from the heat and let them rest for 5 minutes.

Slice the ribeye steaks and serve topped with slices of the smoked leek compound butter. Garnish with freshly chopped chives.