Pan fry the cauliflower rice in oil over medium/high heat until browned. Transfer to greased 2 quart rectangular casserole dish and spread in an even layer.
Mix ground beef, garlic powder, pepper, salt, mustard, Worcestershire sauce and seasoning.
Brown ground beef in large pan over medium/high heat, keep beef in large bite sized pieces. Using a slotted spoon, transfer to casserole dish in an even layer on top of cauliflower rice.
Top with shredded cheese. Broil on high for 2-3 minutes to melt cheese.
Top with sliced tomatoes, chopped lettuce and sliced pickles.
Mix mayo, ketchup and chili powder. Serve with casserole.