Focaccia with onions

Dough

• 20 g olive oil, plus extra for greasing
• 600 g bread flour
• 30 g fresh yeast, crumbled
  hoặc 3 tsp dried instant yeast (12 g)
• 380 g water
• 1 pinch sugar
• 1 tsp salt

Topping

• 40 g extra virgin olive oil
• 40 g water
• 1 ½ tsp salt
• 300 - 350 g onions, cut in halves