Begin by cooking your pasta according to the package instructions (this should take about 10-15 minutes). Once cooked, strain, & set aside for later.
While the pasta is cooking, preheat your oven to 400F and chop your leeks.
Add the chopped leeks to a large baking tray and top with the avocado oil, garlic powder, chili flakes, salt, and pepper. Then, use your hands or a spatula to mix until the leeks are evenly coated with the seasoning.
Next, add the leeks to the oven and cook for 15-20 minutes, making sure to stop and stir the leeks at the 8-minute mark. If the leeks aren't as crispy as desired at the 20-minute mark, you can also broil them for an additional 2-3 minutes. Once cooked, set aside.
While the leeks are cooking, add your almond/soy milk, vegan butter, lemon juice, lemon zest, nutritional yeast, and garlic powder to a large saucepan. Bring to a simmer and cook 5-8 minutes, stirring occasionally.
Next, add in the cooked pasta and frozen/fresh peas and stir. Cook about 5 more minutes until the peas are warmed throughout and the pasta is evenly coated in sauce.
As a final step, add the crispy leeks into the pan and mix them together.
Remove from the heat and top with optional fresh oregano or vegan parmesan. Serve and enjoy!