Combine lime juice, soy sauce, mustard powder, garlic, ground pepper, green onions or shallots, swerve and extra virgin olive oil in a mixing bowl. Mix well, then set set aside.
Place fish fillets into a baking bowl/pan and pour marinade over them, soaking well.
Allow to Marinate in the refrigerator for about an hour
Heat a pan or electric griddle to medium heat
cook until internal temperature of the fillet is about 145° Basting with marinade (We ended up using the entire rest of the marinade)
Serve & Enjoy!