Soft and chewy sourdough foccacia topped with cheese and garlic is the perfect side for any Italian meal. It’s like one big giant bread stick only easier to make!
In a large glass or plastic bowl, mix together sponge ingredients. Allow to sit for at least a couple of hours but as long as overnight. It should be bubbly when it is ready to proceed.
Stir in the additional olive oil, salt and start with 3 1/2 cups of additional flour. Mix until well combined and start to knead on a floured surface. Slowly add flour a little at a time as necessary. The mixture should be soft and moist but not stick after 5-7 minutes of kneading.
Put dough in an oiled bowl. Cover and allow to rise for 1 1/2 -2 hours or until doubled in size. Punch the dough down and place in an oiled sheet pan.
Use your fingers to press the dough to the edges of the sheet pan. Cover with a damp towel and allow to rise for another hour.
Press your fingers randomly into the dough to create the trademark foccacia dimples. Gently brush with remaining oil and sprinkle with garlic salt.
Bake at 450°F for 15 minutes. Remove bread from oven and sprinkle with mozzarella and return to oven for 5-10 minutes more or until bread is done and cheese is lightly golden.
Cool then cut into pieces and serve. Store extras in an airtight bag.