Preheat oven to 375 degrees F (190 C) and lightly grease a 9x13 inch (or similar size) baking dish (adjust number/size of pan if altering batch size).
Prepare your cauliflower rice (either with the shredding attachment on your food processor or a box grater). Set aside.
Lightly steam your broccoli - just until it has a slight bite - either in the microwave in 45-second increments or on the stovetop using a steamer basket in a saucepan with 1-2 inch of water). Place in refrigerator for later.
Next prepare your sauce. Heat a large, oven-safe skillet over medium heat. Once hot, add oil and minced garlic. Stir and cook for 1-2 minutes, or until light golden brown, then add arrowroot starch and whisk - cook for 1 minute.
Slowly add almond milk while whisking, then cook for 2 minutes over medium heat, stirring frequently. The sauce will likely look a little clumpy - that’s OK! We’re going to blend it.
Transfer mixture to a blender, along with 1/4 tsp each salt and pepper (amount as original recipe is written // adjust if altering batch size), nutritional yeast, and vegan parmesan cheese and blend on high until creamy and smooth, scraping down sides as needed.
Taste and adjust seasonings as needed - you want it pretty well salted + cheesy, so don't be shy with the nutritional yeast, salt, and vegan parmesan cheese.
Return sauce back to skillet from earlier and cook over low heat until warmed and slightly thickened - about 2-3 minutes - whisking occasionally. As it warms back up, it will thicken (see photo). For a thicker sauce, leave it as is. To thin slightly, add almond milk 1 Tbsp at a time until desired consistency is achieved. Turn off heat if it starts bubbling too aggressively or gets too thick.
Heat a separate skillet over medium heat. Once hot, add 1 Tbsp oil (amount as original recipe is written // adjust if altering batch size) and cauliflower rice. Season with salt and pepper and stir to coat. Then cover and let cook/steam for 2 minutes. Remove cover, stir and cook for 1-2 minutes more or until slightly softened. Transfer to a large mixing bowl.
Add the steamed broccoli to the mixing bowl and season liberally with salt, pepper and half of the vegan parmesan cheese (1/4 cup as original recipe is written // adjust if altering batch size). This step is important to infuse plenty of flavor into the dish. Stir to coat. If adding chickpeas or kale, add at this time (optional).
Add all of the sauce to the mixture and stir to coat. Then transfer to your greased baking dish and top with another sprinkle of vegan parmesan cheese.
Cover with foil and bake at 375 degrees F (190 C) for 20 minutes. Then remove foil and bake at 400 degrees F (190 C) for 5-15 minutes more or until bubbly and slightly golden brown. You are looking for golden brown edges and a bubbly center.
Remove from oven and let cool slightly. Then serve as is or with a garnish of more vegan parmesan cheese and/or fresh chopped parsley for some color - optional.
Best when fresh. Store leftovers covered in the refrigerator up to 4 days, or in the freezer up to 1 month. Reheat in the oven at 350 degrees F (176 C) until warmed through.