Rub your Kansas City Strip Steaks evenly with the seasoning and salt and pepper and let sit for twenty minutes. Meanwhile, make the tzatziki sauce. Combine garlic, dill, yogurt and diced cucumber in a bowl with salt and pepper and mix to taste. Put the boleo in a warm oven for five to ten minutes, to heat through. In a hot pan cook your steak to medium, around four minutes per side. Remove from heat and let rest five minutes. Slice the steak on a diagonal. Slice the bread lengthwise and a steak on each loaf, top with tzatziki, lettuce, feta and tomato, onion and serve.