Heat the butter in a large skillet over medium-high heat.
Season the salmon fillets with salt and black pepper.
Place the salmon into the skillet skin-side up. Cook for 3–5 minutes until beautifully golden.
Flip and cook another 3–4 minutes, or until the thickest part reaches an internal temperature of 145°F (63°C).
Transfer the salmon to a plate and loosely cover with foil.
Reduce the heat to medium.
Whisk together the orange juice, honey, soy sauce, garlic, and the cornstarch mixed with water if using.
Pour the sauce into the skillet and cook for 30–60 seconds until slightly thickened.
Return the Orange Glazed Salmon to the skillet and spoon the glaze over each fillet.
Garnish with fresh orange slices and serve immediately.