Before you are ready to bake the pizzas, preheat the oven with a pizza stone inside for 30 minutes to 500 degrees F.
Cut the salmon into paper-thin slices. Reserve.
Roll or stretch the dough into 4 (8-inch) circles. Place the pizzas on a lightly floured wooden peel. Brush the center of each pizza to within 1 inch of the edge with olive oil and sprinkle it with some of the red onion. Slide the pizza onto the stone and bake 8 to 12 minutes or until crust is golden brown. Remember that the oven is very hot and be careful as you place the pizza into and out of the oven.
Mix the dill with the sour cream or creme fraiche and freshly ground pepper to taste. Transfer the pizzas to heated dinner plates and spread them with the sour cream mixture.
Divide the salmon, and arrange decoratively over the cream. Place a spoonful of golden caviar in the center of each pizza, then spoon a little of the black caviar into the center of the golden caviar.
In a small bowl, dissolve the yeast and honey in 1/4-cup warm water.
In a mixer fitted with a dough hook, combine the flour and the salt. Add the oil, yeast mixture, and the remaining 3/4 cup of water and mix on low speed until the dough comes cleanly away from the sides of the bowl and clusters around the dough hook, about 5 minutes. (The pizza dough can also be made in a food processor fitted with the steel blade. Pulse once or twice, add the remaining ingredients, and process until the dough begins to form a ball).
Turn the dough out onto a clean work surface and knead by hand 2 or 3 minutes longer. The dough should be smooth and firm. Cover the dough with a clean, damp towel and let it rise in a warm spot for about 30 minutes. (When ready, the dough will stretch as it is lightly pulled).
Divide the dough into 4 balls, about 6 ounces each. Work each ball by pulling down the sides and tucking under the bottom of the ball. Repeat 4 or 5 times. Then on a smooth, unfloured surface, roll the ball under the palm of your hand until the top of the dough is smooth and firm, about 1 minute. Cover the dough with a damp towel and let rest 15 to 20 minutes. At this point, the balls can be wrapped in plastic and refrigerated for up to 2 days.
To prepare each pizza, dip the ball of dough into flour, shake off the excess flour, place the dough on a clean, lightly floured surface, and start to stretch the dough. Press down on the center, spreading the dough into an 8-inch circle, with the outer border a little thicker than the inner circle. If you find this difficult to do, use a small rolling pin to roll out the dough.