Heat the butter in a large skillet over medium-high heat. Season the salmon fillets with salt and pepper, then place them in the pan, skin side up. Cook for 3-5 minutes until the top is golden brown. Flip the fillets and cook for an additional 3-4 minutes, or until the internal temperature reaches 145°F when measured at the thickest part. Once cooked, remove the salmon from the skillet and place it on a plate, covering it with foil to keep warm.

Lower the heat to medium and return the skillet to the stove. In a bowl, whisk together the fresh orange juice, honey, soy sauce, minced garlic, and the cornstarch slurry if you are using it. Pour this mixture into the same skillet and cook until hot, stirring continuously. If using cornstarch, the mixture will thicken in about 30-60 seconds.

Return the cooked salmon fillets to the skillet and gently coat them with the orange glaze. If desired, add additional orange slices for garnish and flavor.