Boil a pot of salted water for your pasta. Cook pasta according to package. Then drain and set aside.
In the same pot or in a deep pan, melt 2 tbsp butter on low-medium heat.
Once butter is melted add 1/4 cup flour and whisk for about 30 seconds. Try to get the clumps out as best you can.
Add 2 cups non-dairy milk, 1/4 nutritional yeast, 1/2 tsp sea salt, and 1/2 tsp black pepper. Cook on low-medium heat for 5-8 minutes and whisk regularly until the sauce starts to thicken up.
While the sauce is cooking, in a separate small pan heat 1 tbsp olive oil. Saute jalapeno, bell peppers, mushrooms, garlic powder, basil, and corn on medium heat for 5-7 minutes.
Combine pasta with the cheesy sauce and stir it up. Then stir in the sauted veggies and add the diced tomato.