Pour the water into a bowl, add the yeast, a pinch of sugar and a few tablespoons of flour. Stir to dissolve the yeast. Leave for 15 minutes.
Add salt.
Stirring with your hand, slowly add flour.
When the dough starts to pull away from the edges of the bowl add olive oil.
Keep kneading. Transfer the dough to the countertop.
Dough should be soft and elastic. If it still sticks to your hands it's nothing. Knead for a while sprinkling not too much flour or semolina. Slightly sticky dough is better than a rock hard dough.
Brush the dough with olive oil and leave it to rise. Let the dough double in volume.
Stretch the dough into a thin sheet starting from the middle. Do not roll it out.
Leave for 5 minutes.
Slice the onion. Place on focaccia and press into dough.
Arrange the grapes on the dough.
Sprinkle with salt and oil generously.
Bake at 200-250 degrees until the edges are browned.
After baking sprinkle with oregano or thyme.