To make the falafel
Preheat the oven to 110°C/225°F/gas mark ¼.
Combine the ground flax seeds and sesame seeds in a bowl and set aside.
Combine the carrots, mushrooms, onion, garlic and 2 tablespoons of the olive oil in a separate bowl. Add a pinch of salt and mix well. Place the pistachios, almonds and sunflower seeds in a food processor and process to a crumbly texture. Add the nut mixture to the vegetable mixture, together with the parsley, cumin and lemon juice. Mix thoroughly and season to taste with black pepper.
Form the mixture into balls 3–4 cm (1¼–1¾ inches) in diameter. Roll the falafel balls in the flax- and sesame-seed mix to coat well. Place on a baking tray (cookie sheet) and bake for about 40 minutes, or until crisp on the outside but still moist.
Serve the falafels, lettuce wraps, tomato salsa and mint yogurt in separate bowls. To assemble, place 3 falafels in a lettuce wrap and add a spoonful each of tomato salsa and mint yogurt.
To make the iceburg lettuce wraps
Chop the root off the lettuce and carefully peel away the large outer leaves. Place them in a large bowl of cold water until you are ready to serve, to keep them crisp and fresh. Pat dry to use.
To make the mint yoghurt
Place the yogurt in a bowl. Just before serving, finely chop the mint and stir into the yogurt (don’t chop before you are ready as the mint will turn black).
To make the tomato salsa
Place all the ingredients in a bowl and mix gently to combine.