1 small onion, chopped
1 (5 ounce) can tuna packed in water, drained
1/4 cup grated Parmesan cheese
1/4 cup mayonnaise
2 egg, beaten
2 tablespoons Dijon mustard
2 teaspoons salt-free seasoning blend (such as Mrs. Dash(R))
1 teaspoon paprika
1 teaspoon dried sweet basil
1 (3.5 ounce) bag pork rinds, crushed
butter-flavored cooking spray
Mix mackerel, onion, tuna, Parmesan cheese, mayonnaise, eggs, Dijon mustard, seasoning blend, paprika, and basil together in a bowl. Add pork rind crumbs, 1 to 2 tablespoons at a time, until mixture holds together. Form mixture into balls and flatten into 1/2-inch-thick cakes. Heat a large non-stick skillet over medium-high heat and grease with cooking spray. Arrange cakes in the hot skillet and spray each cake with cooking spray. Cook cakes, working in batches if needed, in the hot skillet until browned, 3 to 5 minutes; gently flatten cakes with the back of a fork. Flip cakes and cook until other side is browned, 3 to 5 minutes. Transfer cakes to a paper towel-lined plate.