Place all salsa ingredients into a bowl and gently fold together until fully combined. Season with salt and pepper and fold a few more times. Set aside.
Brush each steak with ½ tablespoon oil and rub with 1 tablespoon garlic and herb seasoning, on both sides. Season with salt and pepper. Set aside.
In a mixing bowl, toss together shrimp with 1 tablespoon oil and remaining tablespoon seasoning. Season with salt and pepper and toss shrimp once more.
Heat grill or grill pan over high heat and brush with ½ tablespoon oil.
Place steaks on grill and sear steaks for about 4 minutes. Flip each steak and grill for an additional 3 to 4 minutes for medium rare or 5 to 6 minutes of medium doneness. Remove steak from heat and set aside onto a cutting board. Allow steaks to rest for 5 to 7 minutes.
Brush remaining ½ tablespoon oil onto grill and add shrimp. Grill shrimp for 3 to 4 minutes. Flip shrimp and continue to grill for an additional 3 to 4 minutes. Remove from heat and transfer to a serving platter.
Slice steak into ½ inch strips, transfer to serving platter with grilled shrimp and serve with avocado, tomato and cucumber salsa on top or on the side.