Dissolve the yeast in water and stir in the olive oil. Add the flour a little at a time until into the mixture becomes kneadable. Add salt and knead about 5-7 minutes. Leave to rise 1 hour.
Roll the dough out thinly and cut out small circles. Cover each circle with sour cream and thinly spread sliced onions and cubes of bacon. Add slices of Castello Extra Creamy Brie, salt and pepper.
Bake at 230 celsius for about 10 minutes, or until it turns golden brown and the cheese melts.