Simple flatbread with onion and tuna

Ingredients

• 200g of whole wheat or spelt flour
• 1/2 tsp of salt
• 150g of plain yogurt
• 1 tbsp of olive oil
• a handful of cherry tomatoes
• 1 tsp of olive oil
• 200g of tuna fillets in brine
• 1 large red onion
• 70g of black olives
• a handful of fresh herbs