For the salmon:

1. Melt butter in a large cast-iron skillet over medium-high heat.
2. Season salmon fillets with salt and pepper.
3. Add salmon fillets, cooking for about 3-5 minutes on each side until the internal temperature has reached 145 degrees F (63 C) and the salmon flesh flakes when tested with a fork. Cast-iron conducts heat really well so if you feel that your salmon is browning too quickly before reaching this internal temperature you can turn the heat down a bit. Remove salmon from the pan with your fish spatula and set to the side.

For the whisky cream sauce:

1. Turn heat down to medium-low as the cast iron skillet should be piping hot at this point. Deglaze the pan with the whisky, scraping up any bits of salmon and pepper with your fish spatula as the alcohol cooks down.
2. Allow the whisky to reduce by half then add the heavy cream to the pan and stir vigorously with a wooden spatula or a whisk to incorporate.
3. Add the butter and Dijon mustard and continue to whisk until the sauce begins to thicken, then remove from heat.

For the cheddar mashed cauliflower:

1. In a large, microwave-safe bowl combine chopped cauliflower, butter, and 2 tbsp of heavy cream.
2. Microwave for 6 minutes. Remove from heat, stir, and microwave for an additional 6-7 minutes. The cauliflower should be easily speared with a fork at this point.
3. Add cauliflower, the remaining 2 tbsp of heavy cream, and the shredded cheddar cheese to your food processor. Pulse until well-blended and creamy. If you do not have a food processor, this can be done in a blender or even with a hand mixer, though I find it turns out creamiest in a food processor.
4. Add salt and pepper to taste, blending to incorporate.

To assemble:

1. Portion the mashed cauliflower onto each plate and layer with a salmon fillet. Spoon whisky cream sauce liberally over the top and garnish each plate with chopped chives.