Whisk together the avocado oil, lemon juice, dill, capers, pepper, and water until everything is thoroughly combined and the mixture thickens slightly.
Place your protein of choice in a shallow dish or resealable bag. Pour in the marinade, ensuring all pieces are evenly coated.
Cover and marinate in the fridge for at least 1 hour, up to overnight for the deepest flavor.
When you're ready to cook, remove the protein from the marinade and pat it dry for the best browning and texture.
Discard any used marinade that has come into contact with raw meat or seafood.