In a medium bowl, add all the veggies, and season with 2 tablespoons of olive oil, salt, and pepper.
Remove the sheet from the oven, and place all the veggies on the same baking sheet. Spread everything out in an even layer, and roast for 10 minutes more.
While the chicken and veggies are in the oven, prepare the mashed cauliflower.
For the mashed cauliflower
Fill a large pot with about 2 cups of water, and bring it to a boil.
Then, place a steamer basket in the bottom of the pot.
Add the cauliflower florets to the steamer basket.
Cover the pot, and steam until the cauliflower is fork-tender, about 6-8 minutes. Remove from the heat, uncover the pot (this step is important), and let the cauliflower cool for 5 minutes.
Place the steamed cauliflower and garlic in a blender jar, and blend until the cauliflower is completely smooth. Transfer to a bowl, add the clarified butter, mayo, salt, and ground black pepper, and stir well to combine.
Taste to adjust the seasoning.
Place an even amount of chicken, veggies, and mashed cauliflower into 4 glass containers. Cover with the lid, and place in the fridge for up 4 days. Heat in the microwave for about 1½-2 minutes. The time depends on the power of your microwave.