If adding the mushrooms, sauté 4-6 ounces of mushrooms in a pan on the stove. Sauté the mushrooms for for about 5 minutes. You can use water, veggie broth or oil if you prefer. Then set them aside.
For the cheese dip, in a high speed blender or food processor, blend together the first 6 ingredients with JUST the liquid from the can of diced tomatoes. Set the tomatoes aside.
Once you have the creamy blend, pour in a bowl & mix in the canned tomatoes & mushroom.
To heat, you can use a crockpot or on the stove pot over low-medium heat. Store leftovers in the refrigerator for 3-4 days in an air-tight container.
Notes
If you have a high speed blender like a vitamix, you could get away with not soaking the cashews. If you don't have a high speed blender definitely soak the cashews. They can even be soaked overnight.
For the diced tomatoes - I like the 365 organic brand at Whole Foods that also has jalapeño and cilantro in it. If you can't find that, just diced tomatoes works too. A 14 oz can will also work.
The mushrooms can be left out! It will not change the recipe at all.