It's not quite mac and cheese, but sometimes I make a really tasty sauce by blending roasted butternut squash, caramelized onion, nutritional yeast, soymilk, salt and pepper in my food processor.
I have also made a garlicky alfredo version using steamed cauliflower, caramelized onion, garlic, white beans (optional), nutritional yeast, miso (optional),soy milk, salt and pepper.
When I want something more like a mac and cheese, there are cashew/sunflower seed options that are richer than the purely veggie based versions. Sunflower seeds are cheaper than cashews, so I often go that route.
1/4c raw cashews/sunflower seeds (soaked overnight)
1c cauliflower
1 medium carrot
1 small onion
2 large cloves garlic
1/4c nutritional yeast
1T miso paste
1t spicy mustard
salt, pepper
Drain the soaked nuts/seeds. Steam the cauliflower and carrot until soft. Sautee the onion and garlic in a little oil until caramelized, blend the nuts/seeds, veggies and remaining ingredients in your food processor until smooth, adding water or soymilk as needed to acheive the desired consistency. Serve over pasta, veggies, as a pizza sauce or however you like (=