4 cups all-purpose flour
1 1/2 tsp active dry yeast
1 1/2 tsp salt
1 1/2 cups warm water
1/4 cup olive oil
1 large red onion, thinly sliced
1/2 cup pitted Kalamata olives, chopped
1 tbsp fresh rosemary, chopped
Sea salt for topping
In a large mixing bowl, whisk together the flour, yeast, and salt. Add the warm water and olive oil and mix until the dough comes together.
Knead the dough on a floured surface for about 5-10 minutes, until it becomes smooth and elastic.
Grease a large mixing bowl with olive oil and place the dough inside. Cover with a damp towel and let rise in a warm place for about 1-2 hours, or until doubled in size.
Preheat the oven to 425°F (220°C). Grease a baking sheet with olive oil.
Punch down the dough and transfer it to the greased baking sheet. Use your fingers to press the dough into a rectangular shape, about 1 inch thick.
Scatter the sliced red onion, chopped olives, and rosemary over the top of the dough, pressing them into the surface slightly.
Drizzle the top of the focaccia with olive oil and sprinkle with sea salt.
Bake for 20-25 minutes, or until the focaccia is golden brown on top and cooked through.
Remove from the oven and let cool for a few minutes before slicing and serving.