1. In a large pot, cook elbow macaroni according to package instructions. Drain.
2. In a medium saucepan add 2 cups of water and insert steamer basket. Add carrots, potatoes, and cashews. Cover with a lid and steam for 15-20 minutes until carrots and potatoes are fork-tender.
3. Add steamed carrots, potatoes, and cashews into a high-speed blender. To it, also add garlic cloves, vegan butter, almond milk, vegetable broth, onion powder, salt, smoked paprika, nutritional yeast, tapioca flour, and lemon juice. Blend on high speed for at least 1 minute or until the mixture is completely combined and smooth.
4. Add cooked pasta back into the large pot and pour "cheese" sauce on top of the pasta. Gently stir together to coat completely. At first, the sauce will be thin, but as you stir, it will thicken up. Allow vegan mac and cheese to rest for 5 minutes and stir again. This will allow the sauce to thicken even more.