Step 1Place the quinoa and1 cup of cold water in a large saucepan over medium heat. Bring to the boil, then cover, reduce heat to low and simmer for 12 minutes, or until the water has evaporated and the quinoa is al dente. Set aside to cool.
Step 2Cook broccoli in a saucepan of boiling water until just tender. Drain. Refresh under cold running water. Drain, and coarsely chop.
Step 3Whisk eggs and flour in a large bowl until smooth. Add quinoa, broccoli, tuna, feta, chives, mint and zest. Season the mixture with cracked black pepper and stir until it is well combined.
Step 4Spray a big, non-stick frying pan with oil and set over medium-high heat. Add 4 x 1/4-cupfuls of mixture to pan, and cook fritters for 2–3 minutes each side, or until golden and cooked through. Repeat with remaining batter to make 16 fritters.
Step 5Meanwhile, combine the cucumber, salad leaves and radishes in a salad bowl. Mix the yoghurt with extra chives, mint and zest. Serve quinoa fritters with salad, lemon and herb yoghurt and lemon wedges.