Set oven to 400F.
Add water to pot with a steamer basket, then bring it to a simmer. Add raw cauliflower to the steamer basket. Cover and cook for about 15 minutes or until the cauliflower can be easily pierced with a fork. Remove the cauliflower from the basket and let it cool.
In a large bowl, mash the cauliflower using a fork or potato masher, then add Greek yogurt and garlic powder. Mix it up using a spatula, then season to taste with sea salt & pepper.
Set a nonstick skillet on medium heat, then add olive garlic, bell pepper and red onion. Cook for about 3 minutes until the red onion turns brown and be careful not to burn the garlic.
Add lamb to the skillet, then chop and mix it up using a wooden spatula. Cook for about a minute, then toss in the seasonings. Cook for about 2 minutes, continually chopping and stirring the meat.
Then, add BBQ sauce, mustard and no salt tomato sauce. Mix it up. Add the frozen vegetables and cook for about 2 minutes.
Add the mixture to mini-baking tins or to medium-size baking dish. Top the mixture with the cauliflower mash, then garnish the top with pepper and/or spray butter or olive oil if desired.
Bake in the oven for 20 minutes at 400F.