Take the steaks out of the fridge and let them rest at room temperature for 20 minutes before cooking.
Place a cast-iron skillet in the oven and set the broiler to 500°F. Once the oven has reached temperature, remove the skillet from the oven.
Pour about 2 tablespoons of avocado oil onto a plate. On a separate plate, mix together the salt and pepper, to taste.
Roll the steaks in the oil and then roll all sides through the salt and pepper mixture. Set aside.
Mix the butter with 2 teaspoons of the fresh herbs and minced garlic. Chill the herbed butter in the fridge until the steaks are done cooking.
Toss the shrimp with the remaining tablespoon of oil and the remaining teaspoon of herbs. Set aside.
Add the steaks to the pre-warmed skillet and place it in the broiler. For steaks with a thickness of about 1 inch, aiming for medium doneness, cook for 4-6 minutes on this side.
Remove the skillet from the oven. Flip the steaks over. Add the shrimp to the skillet in a single layer without overlapping each other or the steaks. Place the skillet back in the oven.
After about 4 minutes, start checking the steaks with a meat thermometer. An internal temperature of 140-145°F indicates medium doneness. The shrimp should also reach an internal temp of 140-145°F, and they should appear pink and opaque throughout as they curl into a gentle "C" shape.
Remove the skillet from the oven when both the steaks and shrimp have reached their optimal internal temperature. Immediately place the herbed butter on top of the steak and shrimp.
Let the dish rest for 5-10 minutes. Plate and serve while hot.