You've heard of and seen floral focaccia bread art everywhere, but have you seen it like this before? This 4th of July, get festive with a patriotic Flag Focaccia! It's fun to make and a real show-stopper!
In a measuring glass or bowl, combine the warm water, yeast and sugar. Allow to rest for about 10 minutes, until foamy and frothy.
In the bowl of a stand mixer, fitted with the dough hook, combine 5 cups flour, salt, ½ cup oil and the water/yeast mixture. Mix on low until it begins to come together. Increase the speed and knead until the dough pulls away from the sides of the bowl, about 5 to 7 minutes. Add enough of the remaining ½ cup flour as needed to create a smooth dough yet is still slightly sticky to the touch.
Transfer to a floured work surface and knead a few times. Shape it into a ball and place in an oiled bowl, turning over to coat both sides. Cover loosely with plastic wrap and a damp kitchen towel and let rest until doubled in size, about 1 hour.
Drizzle the remaining ¼ cup olive oil onto the bottom of a half sized baking sheet (18 in × 13 in). Transfer the risen dough onto the oiled baking sheet and stretch it out to cover the bottom of the pan completely. Use your fingers to make indentations throughout the dough. Cover loosely with plastic wrap and a damp kitchen towel and let rest until doubled in size, about 1 hour.
Preheat oven to 425°F.
Uncover the risen dough and then lay out the thinly sliced potatoes in an overlapping square at the top left corner of the pan. This will be the blue section of the flag. Use the sliced red bell peppers and sun-dried tomatoes to create the stripes.
Bake until the top is golden brown, about 25 to 30 minutes. Remove from the oven and immediately sprinkle some feta over the potatoes, to create the stars. And then create the white stripes by sprinkling the empty spaces with feta as well. Allow to cool before slicing and serving.