Preheat your oven to 400°F and line a small baking sheet with parchment paper.
Toss the asparagus spears with half of the olive oil and a pinch of sea salt, then roast for 12-15 minutes until tender-crisp.
While the asparagus roasts, steam the cauliflower florets until they are very soft, about 8-10 minutes.
Transfer the steamed cauliflower to a blender or food processor, add the nutritional yeast and a splash of water, and blend until completely smooth and velvety.
Pat the salmon fillet dry and season with salt and pepper.
Heat the remaining olive oil in a non-stick skillet over medium-high heat.
Place the salmon skin-side down in the pan and sear for 4-5 minutes until the skin is crispy.
Flip the salmon and cook for another 2-3 minutes until cooked through to your preference.
Plate the cauliflower mash first, top with the seared salmon, and serve the roasted asparagus on the side with a fresh lemon wedge.