Preheat your oven to 400°F (200°C).

In a bowl, toss the quartered red onions with 1 tablespoon of olive oil, salt, and pepper. Spread the onions on a baking sheet in a single layer.

Roast the onions in the preheated oven for about 25-30 minutes or until they are tender and caramelized, flipping them halfway through for even cooking.

While the onions are roasting, season both sides of the ribeye steaks generously with salt and freshly ground black pepper.

In a small bowl, combine the crushed coriander seeds and the remaining tablespoon of olive oil. Rub this mixture onto both sides of the ribeye steaks.

In a large oven-safe skillet, heat a little oil over medium-high heat. Once hot, add the ribeye steaks and sear for 4-5 minutes on each side, or until a nice crust forms.

Once seared, transfer the skillet with the ribeye steaks to the oven (along with the roasting onions) and cook for an additional 5-10 minutes for medium-rare, or until your desired doneness is reached.

While the steak and onions finish roasting, prepare the whipped butter. In a mixing bowl, combine the softened butter, chopped jalapeño, chopped cilantro, lime juice, and salt. Use a hand mixer or a fork to whip the mixture until creamy and well combined. Set aside.

Once the ribeye steaks are cooked to your liking, remove them from the oven and let them rest for 5-10 minutes before slicing.

Slice the ribeye steaks and serve them warm, topped with the whipped jalapeño and cilantro butter and accompanied by the roasted red onions.