Soak cashews overnight. If you don't have time for this step, add boiling water on top of cashews, and soak for 30 minutes. Drain before using.
Add soaked cashews, diced tomatoes, tomato paste, salt, cumin, oregano, dried garlic, onion powder, and optional chili flakes, to a blender. Blend on high speed until very smooth. Set aside.
In a large skillet over medium high heat, add olive oil, onions, and garlic. Saute for 5-7 minutes until just beginning to brown.
Add the carrots, broccolini and asparagus (or desired veggies) to the pan, and saute for another 5 minutes, until tender. Set veggies aside.
In the same pan, add 2 1/2 cups of water, the pasta, and the creamy tomato sauce. Stir together to keep the pasta from sticking.
Simmer the pasta in the sauce for 12-14 minutes, until pasta is done to liking. Use the other 1/2 cup of water to thin out if necessary. I like the sauce on the thinner side, so I use the full 1/2 cup.
Top the pasta with veggies and serve immediately -- the pasta will continue to cook in the sauce if it isn't served right away.