Put the water, yeast, and salt into a large bowl. Stir until yeast is dissolved.
Stir in olive oil.
Slowly mix in the flour until a dough is formed. Knead in a stand mixer or turn out and knead on a lightly floured surface for about 5 minutes.
Place the dough into a greased bowl, then roll the dough so the entire dough ball is coated with oil. Cover with a clean kitchen towel and allow to rise until doubled in size, about 1 hour.
Punch down dough and knead out bubbles. Divide the dough into thirds. You will only need 1/3 of the dough for this recipe. You may reserve the extra for another time or double/triple the topping recipe to make extra pizza.
Preheat oven to 450°F
In a large frying pan, sauté the onion with 1 tbsp oil until caramelized and a rich golden brown.
Grease a large baking sheet with the remaining oil. Form the dough into a fish shape if desired. To give the tail more definition, you may want to twist the tail section (like a pretzel).
Spread the lemon-dill pesto evenly over the dough, leaving the edge bare for the crust.
Spoon the shredded dill havarti over the pesto, then evenly sprinkle the onion, salmon, and capers over the pesto and cheese.
Bake in center rack of oven until cheese is browned and bubbling, about 20 minutes.