Heat the Earth Balance spread (or olive oil) in a large skillet over medium-high heat. Once the spread melts (or oil is shimmering), add in the garlic and red pepper flakes. Cook for 30 seconds or until fragrant.
Add in the brussels sprouts and celeriac noodles and season with salt and pepper. Cook until celeriac pasta is cooked to your consistency preference, about 7 minutes.
Transfer the noodles to a bowl or plate and garnish with parsley. Serve.