The pasta is best fresh while it’s the creamiest. After storing it thickens considerably. Consider cutting the recipe in half if you only need 2-4 servings. You can store leftovers in the fridge for up to 5 days. It still takes great after storing, just keep in mind its drier after storing as the pasta absorbs the sauce.
If you want to add additional veggies, such as zucchini, bell pepper, asparagus or broccoli, add them when you cook the onion or steam or roast separately and mix them in at the end.