In a large bowl, combine together the yeast, sugar and warm water. Cover with cling film and place in a warm position until bubbles begin to appear. Combine in the olive oil, salt and all the flour gently, mixing well and adding more flour if required. Knead on a floured board for 5 minutes until smooth and elastic.
Place into a large oiled bowl covered with plastic film and leave in a warm place, until doubled in size. Remove from the bowl and knock down onto a floured board. Divide into two and knead to make round balls. Roll out into your desired shape and place onto lightly oiled ‘pizza’ trays and hold until required.
Preheat the oven to 240°C. Place the roasted onions and pumpkin randomly onto the pizza dough.
Place the torn mozzarella around the onions.
Break the hot smoked salmon into pieces and spread over the top.
Bake until golden and crisp, and then scatter with the rocket, olive oil, lemon juice and seasoning.