Since our young days as a couple we've made this dozens of times, and I'm still amazed that it's made with potatoes—who knew?! The recipe below makes one thick and poofy focaccia that's lighter than it looks thanks to the velvety olive oil and creamy potatoes. (Keep this in mind when you have Thanksgiving leftovers!)
Our staple toppings are usually a smattering of pesto, sun-dried tomatoes, olives, rosemary, and Parmesan cheese. But sometimes we get creative and add mushrooms, onions, bell peppers, or other veggies we have on hand. I also suggest using a good extra-virgin olive oil—a little bit goes long way, so bust out your good stuff!
Oh, one other note: this is addicting. Consider yourself warned!
by The Tale of Two Kitchens
1 cup room-temperature mashed potatoes (we use instant potatoes if we don't have "real" potatoes on hand)
1 1/2 tsp active dry yeast
1/4 cup water, warm
1 cup water, room temperature
3-4 Tbs extra-virgin olive oil, divided
3 3/4 cup all-purpose flour
2 tsp salt
1/4-1/2 cup Parmesan cheese
sprigs of rosemary
2-3 Tbs pesto
12-15 olives (green and/or black) cut in half
1/2 oil-packed sun-dried tomatoes, drained and chopped
2-3 mushrooms, sliced or chopped
1/2 onion, sliced or chopped
1 bell pepper, sliced or chopped
In medium-sized bowl whisk yeast into warm water and let stand until creamy, about 10 minutes. Stir in remaining water (room temperature) and 1 tablespoon of oil. Combine mashed potatoes (room temperature—if it's hot it'll kill the yeast), flour, and salt into yeast mixture and stir for about 3 minutes. Continue stirring until it gets too difficult, then mix with your hands. Knead until dough is velvety, elastic and slightly sticky. Place dough on a clean, lightly floured workplace and continue kneading until dough is no longer sticky (add a more flour a little bit at a time if necessary). Drizzle 1/2 tablespoon of oil in empty bowl, then place dough back in bowl. Flip dough to get it covered in oil; cover bowl with plastic wrap or a towel and let rise until doubled (about 2 hours).
Preheat oven to 400F.
Spread dough onto a well-oiled cookie sheet (9x13"). Cover with towel and let double (about 1 hour). Once doubled, press your fingertips into dough to create "dimples." Spread pesto evenly across the top, scatter on your toppings (except sun-dried tomatoes*), and sprinkle cheese and rosemary. Drizzle remaining olive oil, making sure to cover edges and corners.
Bake for ~20 minutes, adding sun-dried tomatoes just as focaccia is golden brown.