Dissolve salt, sugar, and yeast in the warm water and allow the yeast to proof. ("Proofing" the yeast is testing it for viability. It will develop a foam which looks like the head of a beer. If it doesn't proof, the yeast is dead and should be discarded.) Proofing takes about 15 minutes. Place flour in a food processor fitted with a dough blade, and through the feed tube with the food processor running, slowly pour in the proofed yeast mixture, until the dough comes together and is a cohesive mass. Transfer the dough to a floured board, and knead for about 5 minutes. Place in a bowl, cover with a clean dish towel and allow dough to rise, so that it roughly doubles in volume. (This will take about 30 minutes to hour). The dough has risen enough if you make an indentation with your finger and it does not spring back.) Punch the dough down and divide into 6 equally sized balls. Cover with towel and allow it to rise again. (Allowing the dough to rise a second time gives it a finer texture.) Note: It will not rise as much the second time.
While the dough is rising, prepare the pizza topping. Heat 1 tablespoon of the oil over medium- high heat in a large saute pan and saute garlic and onions until the onion begins to turn translucent. Season halibut fillets with salt and pepper and sear each side, leaving each side undisturbed for the first minute to allow the flavors to integrate into the surface of the fish. Cook further until the fish flakes, approximately another 6 to 8 minutes, and let rest. Flake the fish and fold into the mashed potatoes.
Preheat oven to 450 degrees F. On a floured surface, stretch the dough into six 6-inch by 8 inch ovals and shake cornmeal over both sides of the dough. (The crust will be par-"baked" on both sides on the stovetop before you add the topping to be baked.) In a heavy bottomed 12 inch skillet which has a lid, heat a small amount of oil over medium heat. (Swirl the oil to coat the entire inside of the skillet.) Transfer teach dough oval to the skillet, allowing one side to lightly cook and stiffen up before flipping it over with tongs. When both sides of each oval are par-baked this way, transfer to a pizza stone. Spoon the potato/fish mixture in the center of the now toasted crust, spreading evenly over the surface. Bake in the oven for about 10 minutes until the tips of the mashed potatoes begin to turn golden.
Remove from oven and sprinkle with salmon, curry powder, red onions, and chives.