Take the steaks out of the fridge 30 minutes before cooking to bring to room temperature. Pat dry with paper towels.

Season both sides of the steaks generously with 1/2 teaspoon salt and 1/2 teaspoon black pepper.

Season shrimp with 1/4 teaspoon salt, 1/4 teaspoon black pepper, and the zest of half the lemon.

Heat the cast iron skillet over medium-high heat. Add 1 tablespoon olive oil and 1 tablespoon butter.

When the skillet is hot and the butter is foaming, add the steaks. Sear for 3-4 minutes per side for medium-rare. During the last minute, add 1 minced garlic clove and baste the steaks with butter.

Remove steaks to a plate, tent loosely with foil, and let rest.

Reduce heat to medium. Add another tablespoon olive oil and the remaining butter to the same pan.

Add the remaining garlic, and sauté for 30 seconds until fragrant. Add shrimp in a single layer. Cook for 1.5-2 minutes per side until pink and slightly golden.

Squeeze the juice of half a lemon and sprinkle with parsley. Remove from heat.

Slice steaks against the grain, plate, and top or serve alongside shrimp. Spoon some pan juices over the top.