In a small saucepan over medium heat, add orange juice and zest, reduce, stirring occasionally, 8-10 minutes.
Stir in brown sugar, honey, tamari, and garlic and bring to a simmer, Cook for 5-6 minutes. Turn off heat and set aside.
In a large skillet over medium-high heat, melt butter.
Add salmon fillets, skin-side up, and sear, about 4 minutes.
Flip fillets and pour the orange sauce over and around them,=.
Continue to cook fillets, for 4-5 minutes, or until fully cooked through.
Remove from pan and arrange on serving platter with sliced oranges (if using).
This salmon is delicious with herbed rice or roasted cauliflower (if you have any orange sauce remaining, drizzle over cauliflower in the last 5 minutes of roasting).