Heat a cast iron or nonstick pan over medium with 1 tablespoon of avocado oil and brown chicken pieces for about 5 to 6 minutes or until browned and cooked. Add more oil mid way through browning if it’s looking dry. Remove chicken pieces from the pan and lower heat to medium low.
Add 2 tablespoons vegan butter, onions, thyme, sea salt and ground pepper to the pan and caramelize onions, only tossing occasionally for about 16 to 20 minutes or until evenly darker brown, caramelized, and soft.
Meanwhile bring a large pot of salted water to a boil and cook macaroni to al dente. Remember to reserve pasta water before draining.
Preheat oven to 400°F.
Remove caramelized onions from the pan and add the reserved pasta water to this pan bringing it to a simmer. Once simmering stir to get all the remaining onion bits off from the bottom of the pan. Pour this onion water into a blender. To the blender add ¼ cup of the caramelized onion mixture. Also add 1 cup mozzarella style shreds, minced garlic, cornstarch, white wine vinegar, dijon mustard, onion powder, and bouillon or worcestershire and blend until very smooth.
Use remaining 1 tablespoon of vegan butter to grease the bottom and sides of your cast iron pan or another oven safe casserole dish. Combine macaroni, chicken pieces, remaining caramelized onions, kale, the blended sauce, and 1 cup mozzarella shreds in the cast iron pan or casserole dish until well mixed. Top with croutons and remaining cup of mozzarella shreds on top.
Bake for 15 minutes at 400°F and then broil for 5 minutes to get the top melted and browned if needed. Serve immediately.