Preheat oven to 180 degrees Celsius (skip this step if you are using the time saver option of not baking).
Place a large saucepan of water on the stove to boil. Ensure there is enough water and space in the pot to fit the pasta and vegetables fully submerged.
Once water is boiling, pour in pasta to cook. Stir pasta to make sure none sticks to the bottom of the saucepan.
When pasta is almost cooked (still a little crunchy) add frozen peas and mixed vegetables to water to cook. It is normal for the water to stop boiling at this point. Press down vegetables with a spoon to make sure they are all fully submerged. Cook for approximately 2 - 5 minutes depending on the size of the vegetables until vegetables are just soft.
Drain pasta and vegetables. Pour back into the saucepan. Pour over cheesey sauce. Mix to combine.
To save time, the pasta can be reheated for a few minutes on the stove and served as is. Top with breadcrumbs and vegan parmesan if desired.
Otherwise, pour pasta into a large baking dish. Top with bread crumbs. Bake in the oven for 10 - 15 minutes until browned and crispy on the top.