Place a large pot of water with 2 tbsp sea salt on stove to bring to a boil to cook pasta.
While the water is heating up, prep the vegetables.
Peel a large red onion and slice in half. Slice each half into strips.
Peel and chop garlic.
Chop the ends off the asparagus and cut each spear into bite sized pieces (about the same length as the Rigatoni).
Chop grape tomatoes in half.
Cook the pasta according to the package directions (about 10 minutes for Rigatoni). Drain but don't rinse.
While the pasta is cooking, heat a large skillet on medium heat with the olive oil. Add the onions, garlic, sea salt, italian seasoning and crushed red chilis. Sauté, stirring often, for about 5 minutes.
Add the veg broth and about 1/4 cup of the pasta water (or extra veg broth) to the pan. Add the asparagus and tomatoes. Stir and cover. Cook for about 5 minutes. The asparagus should be cooked but still have some crunch.
Add the drained pasta and balsamic vinegar to the vegetables and stir to combine.
You can top this pasta with fresh herbs such as parsley or basil and also some vegan parmesan if you have some handy.