In a large mixing bowl, combine lukewarm water, milk, and salt. Gradually mix in all-purpose flour, adding enough to form a soft but non-sticky dough. Knead the dough on a floured surface for about 2-3 minutes until smooth and elastic. Divide the dough into 10 equal portions, cover them with a clean cloth, and let them rest for 30 minutes.

While the dough is resting, finely chop the fresh spinach and onions. Massage the chopped onions in a bowl to release their natural juices. In a separate bowl, combine the spinach with the onions, hot red pepper flakes, black pepper, and salt to taste. For creaminess, mix in the optional Turkish white cheese or feta.

After the dough has rested, lightly flour your work surface. Take one portion of dough and roll it out into a thin sheet, approximately 1mm thick. Rotate the dough as you roll to maintain an even thickness and prevent sticking.

Once you have rolled out a sheet of dough, place a generous amount of the filling on one half, fold the other half over the filling, and seal the edges tightly. Use a fork to crimp the edges for an added seal.

Heat a griddle or large skillet over medium heat and add a little butter or oil. Place the filled gozleme onto the hot surface, cooking for about 4-5 minutes until golden brown. Flip halfway through and brush with more butter or oil as needed.

Once cooked, stack the Turkish Gozleme on a plate and cover with a cloth to keep warm. Slice into wedges for easy sharing.