Use the frying pan that comes with your Trangia cooker for the pizzas. Use your larger pan as a lid when it's time to melt the cheese.
Mix baking powder with flour and salt. Add yoghurt, and mix everything together, it should be a pretty sticky.
Wash the bottom of one of your plastic boxes thoroughly and flip it upside down to use as your rolling surface. Use a bottle or something else cylindrical (like Klean Kanteen bottle) as a rolling pin. Sprinkle extra flour on your rolling surface when rolling out breads, underneath and on top. Flip it several times as you roll it, and add a little more flour under and over each time, until you end up with a nice flat bread that will fit perfectly in your pan. Grill in medium hot dry frying pan, on both sides until cooked.
While one bread cooks, roll out the next one. Don't get too far ahead with the rolling.
When all your flatbreads are ready it's time to make pizza! Lower your heat on your Trangia. Put the flatbread in the pan, while still off the heat. Spread pizza sauce on top, not too much! Add grated cheese, sundried tomatoes and olives, and sprinkle some oregano on top. Cover and cook until the cheese has melted. Top with arugula before serving.