Preheat oven to 425 degrees Fahrenheit.
Bring sweet potato to a boil and cook until tender (about 30 minutes or so).
Once all veggies are diced (including the trimming and removal of brussel sprout's outer leaves and bottom), lightly dress with Extra Virgin Oil and sprinkle with sea salt and black pepper.
Then place veggies on prepared baking sheet (avoiding them to be overcrowded or on top of one another) and place in oven for 35-40 minutes.
Half way through their roast time, lightly toss veggies (turning them over on the other side to char evenly).
Meanwhile, in a small bowl, mix together Extra Virgin Olive oil, Lemon Juice, Sea Salt, Black Pepper, Red Pepper flakes, and Garlic Powder until well combined. Set aside.
Drain fully tender Sweet Potato and mash with a spoon (or use an electric mixer for ultimate creaminess). Add butter and continue to mix well until at desired consistency. Set Aside.
Once veggies are charred and completely roasted, in a large skillet on medium-high heat, add veggies, dressing, and chopped walnuts while lightly tossing until fully coated.
Remove from heat and serve immediately. Garnish with parsley if desired.
Bon Appetit!