Pre-heat oven to 250°C/480°F (with baking sheet inside). Roll out pizza dough on a floured surface until desired size is reached. The rim should be a bit thicker than the center (use fingers to shape if necessary). Transfer dough to parchment paper. Check if parchment paper is heat-resistant for temperature of 250°C/480°F (if not, use stronger parchment paper or baking foil instead).
Cover dough with cold pizza sauce, leaving a 2-cm/0.8-in. thick crust. Make sure you don’t apply too much sauce or leave gaps. Use more or less sauce if needed.
Now, add the cheese. Yes, correct! First the sauce, then the cheese, and the toppings last! Otherwise your creative toppings won’t be visible once baked, and you’ll end up with a cheesy mess. Use any cheese you like (I used grated Gouda, as I think it goes well with tuna), and remember—less is more!
Next, add the toppings. Either put everything on top randomly, or decorate your pizza creatively, as you know—you eat with your eyes first! I started with the tuna (use a fork to break into smaller chunks), followed by onion rings (cut beforehand), and finished off with olives and capers (well drained).
Remove the hot baking sheet from the oven, then quickly place parchment paper with pizza on top. Put it back in the oven and bake at 250°C/480°F for approx. 10 min. Make sure you keep an eye on it, as this is just an estimate. A golden, crispy crust is a good sign that your pizza is ready.
Add chopped oregano and some basil leaves, and enjoy!