Rinse and drain quinoa. Add quinoa and broth (or water) to a saucepan and bring to a boil. Reduce to a simmer, cover and cook for 15 minutes. Fluff with a fork and let cool for 5-10 minutes.
Preheat the oven to 400°F and line a large baking sheet with parchment paper or foil.
Add the sweet potato chunks to a large bowl and toss with 1 Tablespoon oil, ½ teaspoon salt and ¼ teaspoon pepper. Keep the bowl for later use! Add sweet potato chunks to a sheet pan lined with parchment paper or foil and roast for 20 minutes at 400°F, flipping halfway.
Prepare broccolini by adding it to the same bowl you used for the sweet potatoes and tossing it with 1 Tablespoon oil, garlic, ½ teaspoon salt and ¼ teaspoon pepper. When the 20 minutes is up on the sweet potatoes add broccolini to one half of the baking tray and return to the oven to roast for 12-15 minutes, until sweet potatoes and broccolini is tender.
While veggies are roasting prep salmon. Season both sides of each salmon filet with salt and pepper. Place filets skin-side down on a parchment-lined baking dish or tray and roast for 10 minutes at 400°F.
While salmon is roasting, mix together mustard, lemon juice, maple and garlic. Remove salmon from oven, spread sauce over salmon and return to oven for 4-5 minutes or until salmon is cooked through and flaky.
To make the bowls, divide quinoa into 4 servings (about ½ cup). Top with veggies, salmon and a drizzle of lemon vinaigrette.
To meal prep: Add layer of quinoa and top with salmon, then add broccolini and sweet potatoes next to the salmon. Once ready to enjoy, heat if desired and top with a drizzle of dressing.