In a small bowl mix all the ingredients together for the tzatziki sauce and set aside.
Place your pizza dough onto your baking sheet or pizza stone, brush with the olive oil and place in the oven. Bake for 5 to 10 minutes until the crust just starts to turn golden brown.
Remove dough from oven and layer the sliced tomatoes, onions, lamb and then sprinkle the feta on top. Place back into the oven for about another 4 to 5 minutes long enough for the crust to finish cooking.
Remove from the oven spoon on tzatziki sauce, slice and serve!