MIX together the dry yeast, sugar and warm water and leave for 10 minutes to activate. COMBINE both flours and salt in a large mixing bowl then stir in the yeast mixture and 4 tablespoons of olive oil to produce a sticky dough. TRANSFER to a well-floured work surface and knead for around 8 minutes, adding more flour as needed to prevent sticking, until you have a smooth, elastic ball of dough. PLACE the dough in a lightly oiled bowl, cover with plastic wrap, and allow to rise for one hour in a warm place (such as a hot water cupboard). FORM the dough into a focaccia-shaped loaf on a baking tray. USE your finger tips to dimple the surface and brush with 1 tablespoon of the olive oil. TOP the loaf evenly with the cherry tomatoes and sprinkle with the dried rosemary. COVER and prove for another 30 minutes in a warm place. BAKE in a preheated 350°F/180°C oven for 30 minutes. COOL on a wire rack.

Variations: Top the plain dough with caramelized onions, anchovies, olives, and thyme to create a Provençal-style focaccia. Or top with finely grated Parmesan cheese then sprinkle with shredded basil leaves. Try other toppings like thinly sliced zucchini, mushrooms and red onions, or char-grilled peppers and eggplant.