Preheat oven to 400 degrees F. Line a baking sheet with parchment paper and set aside.
Toss the cauliflower florets in 1 tbsp olive oil, 1 tbsp lemon juice and 1/2 tsp salt. Spread onto the prepared baking sheet in one even layer and bake for 15 minutes. Shake the pan to toss the cauliflower around, let it settle back into an even layer, and bake another 10 minutes.
Meanwhile, cook the linguine according to package directions.
While the pasta and cauliflower are cooking, heat 1 tbsp olive oil over medium heat in a large pan on the stove. Add the garlic and sauté 1 minute. Add the white wine and simmer 3-4 minutes until the liquid reduces a bit.
Add the lemon juice and broth and simmer 5 minutes.
When the cauliflower is done, toss it into the white wine sauce. Add the cooked pasta and toss to combine. Add the fresh chopped parsley and red pepper flakes. Taste and adjust seasonings. Add a little more lemon juice or salt if needed.
In a coffee grinder or small food processor, grind the pepitas with the nutritional yeast into a course powder.
Sprinkle the pepita mixture, if using, over the cauliflower and linguine and serve immediately.