Preheat your oven to 425°F for the asparagus and prepare a pot of boiling water for the cauliflower.
Season the salmon fillet with salt, pepper, and a drizzle of lemon juice.
Heat a non-stick skillet over medium-high heat and add a few drops of olive oil. Sear the salmon, skin-side down first, for about 3-4 minutes per side until it develops a golden crust.
While the salmon sears, trim the asparagus ends, toss them in a small amount of olive oil, salt, and pepper, and spread on a baking sheet. Roast in the oven for about 10-12 minutes until tender.
Chop the cauliflower into florets and boil until soft (about 8-10 minutes). Drain well.
In a blender or using a hand masher, combine the cooked cauliflower with the garlic, remaining olive oil, salt, and pepper, and blend until smooth to create a creamy mash.
Plate the dish by placing a generous serving of cauliflower mash, topping with the seared salmon, and arranging the roasted asparagus on the side. Drizzle with a touch more lemon juice if desired.