Heat the oil in a large skillet over medium heat. Once the oil is hot, add the garlic, reduce the heat to medium-low, and cook until the garlic is starting to turn golden on most of the edges.
Then, mix in the onion and the salt. Increase the heat back to medium, and cook until the onion is translucent. Add splashes of water in between to help the onions cook evenly. 3 mins
Now, add in the spinach and pepper flakes and mix in. Cover with the lid and continue to cook for 2 to 3 minutes. If there are some frozen spinach pieces, continue to cook for another 2 to 3 minutes, or until the spinach is cooked through, adding a splash of water if needed. (If using fresh spinach, cook until wilted)
Remove half of this garlic spinach mixture and set aside.
Next, add the mushrooms, balsamic vinegar, and salt. Mix in, then cover and continue to cook until the mushrooms are almost cooked through. Meanwhile blend the sauce.
Blend the drained cashews with the rest of the alfredo sauce ingredients, blending until smooth. I usually blend it for a minute, then let it sit for 3 to 4 minutes, and then blend again for a minute and repeat this 2 to 3 times until the cashews are blended in completely.
Then add the cashew mixture to the skillet when the mushrooms are almost done, and mix well.
Use the half cup of water to rinse out the blender, and add that to the skillet and mix in, then mix in the beans and bring to a boil.
Taste and adjust the salt and flavor, then cover the pan and continue cooking for another minute. (You can also adjust the consistency by adding less or more water, based on how creamy or thick you want the mixture. The cashew mixture will thicken quite a bit as it sits, so if you don't want it to thicken too much, don't cook for too long.)
Once done, open the lid, then add the reserved spinach all over the beans, add some vegan parmesan and pepper flakes and serve with some toasted bread, garlic bread, sourdough or flatbread . You can also serve it over pasta or roasted cauliflower steak.
Storage: store refrigerated for upto 3 days. Freeze for upto 2 months.