Alaskan Salmon stuffed with Cream Cheese and Summer Spinach, topped with Toasted Brown Butter Panko Bread Crumbs and Caramelized Vidalia Onions
- 2 medium Vidalia onions, halved and sliced paper thin (about 4 cups)
- 2 tablespoons unsalted butter
- Kosher salt
- Freshly ground black pepper
- 1 - 10-ounce bag fresh summer spinach leaves
- 1/2 cup cream cheese (about 4 ounces), room temperature
- 1/2 cup mascarpone cheese,* room temperature
- Pinch of ground nutmeg
- 8 - 6 to 8 ounce salmon fillets (each about 1 inch thick)
- 2 2/3 cups Panko breadcrumbs
- ½ cup (1 stick) butter, melted
- Preheat oven to 450. Melt 2 tablespoons butter in a large frying pan over medium-low heat until foaming. Add the onions, and let them cook, stirring rarely, until they are deep golden brown and caramelized, about 45 minutes. Season well with salt and pepper, remove from the pan, and let cool.
- Cook spinach in large pot of boiling water just until wilted, about 30 seconds. Drain; rinse with cold water. Squeeze spinach dry, then finely chop. Place in small bowl. Mix in cream cheese, mascarpone, and ground nutmeg. Season to taste with salt and pepper.
- Cut one 3/4-inch-deep, 2 1/2-inch-long slit down center of each salmon fillet, forming pocket for spinach mixture. Fill each slit with spinach mixture, dividing equally among salmon fillets. (Can be made 4 hours ahead. Cover and chill.)
- Line rimmed baking sheet with non-stick foil wrap. Sprinkle salmon fillets with salt and pepper.
- Mix Panko breadcrumbs and melted butter in medium bowl. Top each salmon fillet with breadcrumb mixture, pressing to adhere. Place salmon fillets on prepared baking sheet. Bake salmon until opaque in center, about 12 minutes. Transfer to plates, top with caramelized Vidalia onions and serve.