Boil water and pour over raw cashews (or sunflower seeds if you're subbing) - let them soak for 10 minutes while you prepare everything else. Drain them once they're done. If you're subbing silken tofu for the cashews, skip this step and just add tofu to the blender with the other cheese sauce ingredients.
½ cup raw cashews
Bring a pot of water to boil and cook your shells according to package. After they're cooked, strain them, but save ½ cup of the water for later.
1 lb dry pasta shells
While shells are cooking, add oat milk, cashews (once they've soaked and drained) nutritional yeast, garlic powder, onion powder and salt to a blender (everything but the shredded cheese, sour cream and pasta basically). Blend until smooth.
½ cup raw cashews, 2 tsp garlic powder, ½ tsp onion powder, 2 tbsp nutritional yeast, 1½ tsp salt, 1¼ cup unsweetened plain oat milk
Once your shells have one minute left of cooking, add your frozen veggie of choice to the pasta water with the shells. This will cook the veggies without having to use another pot. Drain when done, but save ½ cup of the pasta water.
Handful of frozen green veggie of choice like peas or broccoli
Turn the heat to low on the pan you drained the pasta from and add the cashew mixture, the cup of shredded vegan cheese, sour cream and ½ cup of pasta water.
1 cup shredded vegan cheese, ½ cup vegan sour cream
Stir and let it thicken a little. About one minute. If it gets too thick, just add a splash of the oat milk or water
After about a minute, add the pasta shells to the pan and mix it all together. Add more salt if needed.