The night before (poolish)

1. In a medium bowl combine all poolish ingredients. Cover with a towel and let sit for 8 hours. If not using after 8 hours, refrigerate and use within 24 hours for best results.

Day of baking (for bread)

1. Combine poolish in a large bowl with water, olive oil, yeast, and flour. Stir to combine until full incorporated. Mix until it barely forms a ball.
2. On an unfloured surface (or just inside the bowl), knead with your hands for 8 minutes. Alternatively, if you have a stand mixer, feel free to knead with the dough hook for 5 minutes.
3. Add kneaded dough to an oiled mixing bowl and cover with a towel once more. Let sit for 1 hour 15 minutes. It will double in size.
4. Line a baking sheet with parchment paper. Remove dough from bowl and shape into a circle or disk on parchment, about 8 inches in diameter. Make sure no parts of the dough are too thin, you want to maintain a thicker base when possible. Cover with the towel one final time and let proof in a warm space for 50 minutes. While this is proofing, preheat your oven to 450 degrees F.
5. Once your dough is proofed, it’s time to add the potato topping. Combine thinly sliced potatoes in a bowl with a heavy drizzle of olive oil, stirring to coat. Layer across the surface of the focaccia, creating a spiral if you’d like. Scatter minced rosemary on top of potatoes and sprinkle with salt. Add garlic chips if using. Coat once again with olive oil (this will help it get crispy when baked).
6. Bake for 15 minutes, let cool slightly, and enjoy! Bread is best stored in the freezer and reheated in a covered skillet.