1. Preheat the oven to 375 degrees Fahrenheit (190 degrees Celsius). Line a baking sheet with Gefen Parchment Paper.
2. Place the fish, skin side down, on the prepared baking sheet. Drizzle a little silan and mustard on the fish and rub them in using your fingers. Sprinkle with a thick layer of the crumb topping.
3. Roast until the fish is just cooked through, about 12 minutes, depending on the thickness of the fillet. To test for doneness, use a sharp knife to cut through the crumb topping. Peek into the center of the fillet to see if it’s opaque, and then cover up the slit with more crumbs. Serve right away or let cool and serve at room temperature.