1.Place cheese in muslin or paper towel-lined sieve over medium bowl. Drain for at least 1 hour. After draining you should have 1 cup of cheese.
2.Meanwhile, make pizza dough. Combine flour, yeast, sugar and salt in medium bowl; make a well in the centre. Stir in oil and enough of the water to mix to a soft dough. Knead dough on floured surface about 10 minutes or until smooth and elastic. Place dough in large oiled bowl, cover; stand in a warm place about 1 hour or until dough doubles in size. Turn dough onto floured surface; knead until smooth.
3.Preheat oven to 240°C/475°F. Oil two oven or pizza trays; place in heated oven.
4.Divide dough in half; roll each half on floured surface into a 30cm (12-inch) round. Place on trays.
5.Spread bases with cheese. Bake about 10 minutes or until bases are browned and crisp.
6.Meanwhile, combine oil, roe and chives in small bowl.
7.Serve pizzas topped with salmon, fennel, watercress and crème fraîche; drizzle with the oil and roe mixture, serve with lemon wedges.