Start by removing the skin from the fresh salmon filet. Dice the salmon into small pieces, or you can pulse it in a food processor for a finer texture.
In a skillet, heat 2 tablespoons of olive oil and 1 tablespoon of unsalted butter over medium heat. Add the finely diced onion and diced red bell pepper. Sauté until the vegetables are softened and fragrant, about 5-7 minutes. Season with kosher salt and black pepper to taste.
In a large mixing bowl, combine the diced salmon, sautéed vegetables, Panko bread crumbs, slightly beaten eggs, mayo, Worcestershire sauce, sriracha, and Old Bay seasoning. Mix everything until well combined, being careful not to overwork the salmon.
With your hands, form the salmon mixture into patties—about 2-3 inches in diameter and 1 inch thick. You should get around 6-8 patties depending on the size.
In the same skillet, add the remaining 2 tablespoons of olive oil and 1 tablespoon of unsalted butter. Once hot, carefully place the patties in the skillet. Cook for about 4-5 minutes on each side or until golden brown and cooked through.
Once cooked, transfer the patties to a paper towel-lined plate to drain any excess oil. Serve warm with your favorite dipping sauce or on a bed of greens.