Preheat your oven to 425°F. Trim the ends of the Brussels sprouts and halve them. Toss with a drizzle of olive oil, salt, and pepper, and spread on a baking sheet.
Roast the Brussels sprouts for 20-25 minutes until tender and slightly crispy, stirring halfway through.
Meanwhile, steam the cauliflower florets until very tender, about 10 minutes.
In a small pan, heat a teaspoon of olive oil and lightly sauté the minced garlic until fragrant.
Place the steamed cauliflower in a bowl, add the sautéed garlic, a tablespoon of lemon juice, and nonfat Greek yogurt. Season with salt and pepper, then mash until smooth and creamy.
Season the 5 oz salmon fillet with salt and pepper. Heat a skillet over medium-high heat and sear the salmon, skin side down if applicable, for about 3-4 minutes per side until the exterior is nicely browned and the salmon reaches your desired doneness.
Plate the salmon alongside a serving of roasted Brussels sprouts and a generous scoop of garlic mashed cauliflower.
Finish with an optional squeeze of fresh lemon juice over the salmon for extra brightness.