Cheesy Broccoli and Cauliflower

I made this for Chris the other night and he really liked it. So much so that he requested it for lunch for this upcoming week.

I steamed the cauliflower and broccoli in our rice cooker. For the sauce, I used approximately:

1/4 onion
1-2 mushrooms
4-6 tablespoons nutritional yeast
1/2 cup rice milk or coconut milk
1 clove garlic or hefty shake of garlic powder
1/2 tablespoon oil
1/2 tablespoon balsamic vinegar
1 teaspoon soy sauce
1 tablespoon mustard-Sorry forgot to add this in the original post! We use Dijon from Naturally Preferred though any without honey or sugar will do.
hefty shake of italian seasoning
drop of molasses
small drop vanilla
dash of salt and pepper

Sautée onions and mushrooms until golden brown, using oil and balsamic and soy sauce. Add in vegan milk and nutritional yeast and spices. Use a wisk to stir all ingredients, then turn on medium high heat until it starts to boil. Wisk again and let sit a few minutes before you serve over vegetables or pasta for some wholesome mac-n-vegan-cheese. If the sauce is too thin, add in corn starch (worst choice of the three...), arrowroot powder or agar agar. Be sure to wisk thouroughly if you add these thickeners. Enjoy!