Cut your kumquats in half and flick out the seeds or if using an orange, peel it.
Mince your kumquat or orange to a pulp (I used my blender)
Add your softened butter, kumquat or orange pulp, lemon zest, orange zest, and mint leaves to a bowl.
Using a fork, mash it all together until everything is well mixed.
Add a dash of ginger into the butter.
Add salt and pepper to taste.
Mash it all together until you have a nice citrus butter.
Heat a large skillet over medium heat.
Add 1/2 Tablespoon of the citrus butter to the skillet and let it melt.
Rub 1 Tablespoon of the citrus butter over each fillet to coat them.
Add your fillets to your saucepan, cook 4 minutes on 1 side and then flip to cook for an additional 2 to 3 minutes on the other side until the fish is opaque and cooked thoroughly.
Add more butter to melt on top, if desired.
Save any leftover butter in the fridge.