Preheat the oven to 375 degrees. Lightly grease a 9x13 casserole dish. Line the bottom with broccoli florets and brush 2 tsp of oil on top.
Once the oven is hot, transfer the casserole dish with broccoli to the oven. Cook for 17-18 minutes, leave the oven hot once broccoli is removed.
Heat a large skillet to medium high heat. Once hot, coat the pan with 1 tbsp oil then toss in the onion and 2 cloves garlic. Saute for 3-4 minutes, then add the cauliflower rice. Continue to cook the cauliflower rice until fragrant (about 5-6 minutes). Remove the cauliflower rice from heat, keep the skillet hot.
Add the remaining oil to the skillet, and cook the chicken until browned on all sides (about another 5-6 minutes). Remove from heat.
Meanwhile, make the cashew sauce. Place the drained cashews, chicken broth, nutritional yeast, dijon mustard, remaining garlic cloves, and salt to a blender or food processor. Blend until smooth 2-3 minutes. You may need to pause and use a rubber spatula to scrape down the sides. Add an additional tbsp of water if the sauce is too thick.
In the casserole dish with the broccoli, mix together the chicken and cauliflower rice mixture. Pour the cashew sauce on top. Sprinkle with chopped almonds.
Bake for 22-25 minutes or until the nuts are golden brown and the sauce is bubbly. Serve hot.