In a large bowl, mix flour with salt and sugar. Dissolve the fresh yeast in warm water and add to the flour mixture. Add oil and mix everything together.
Using your hands or a mixer, knead until smooth and pulls away from the side of the bowl. Cover it and let it sit for about 1 hour at room temperature, to let the dough rise until doubled in size.
Prepare the tomato sauce.
In a medium sauce pan heat oil over medium-low heat. Add garlic, cook few seconds then stir in paprika and pureed tomatoes. Add sugar, basil, oregano, bay leaf salt and pepper.
Bring to a simmer, lower hea,t and cover. Cook for about 10 minutes or until it has the right consistency for spreading on your pizza. When done, remove from heat and let cool slightly before using on your pizza.
How to shape and bake the pizza.
Preheat the oven to 400°F (200°C). Punch the dough down, knead and split in 2 pieces. Shape each piece into a ball, then roll out into a circle about 12 inches (30 cm) in diameter. Place it in greased pizza pan and punch some holes in the dough with a fork.
Spread tomato sauce over the dough and sprinkle with oregano and basil. Spread half of the tuna chunks, red onion slices and olives over dough and place half of mozzarella slices on top.
Place in the preheated oven, switch for heat coming from down and bake for 15-20 minutes, until the cheese has melted and edges of crust are golden brown.
You can garnish with fresh red onion slices and basil leaves before serving.