Preheat oven to 350 degrees.
Butter 9x13 casserole pan and set aside.
Meanwhile heat butter and olive oil over medium heat.
Add chopped yellow onion and bell peppers and saute 1-2 minutes till fragrant.
Add mushrooms and cook another 8-10 minutes. Drain any excess liquid.
Add kale, garlic powder and cook another 1-2 minutes until slightly wilted.
Spread frozen tater tots out on bottom on 9X13 buttered casserole dish.
Layer mushroom, kale, onion. pepper mixture on top of frozen tater tots and spread out evenly.
In medium mixing bowl beat eggs, sour cream, half & half and cheese reserving ½ cup for topping. Add, salt & pepper to taste and combine well.
Pour evenly over casserole.
Bake in preheated oven 35 -40 minutes.
Five minutes prior to being done top with reserved cheese.