Bagels with healthier tuna salad

• Combine the Greek yogurt, plain flour, baking powder and salt in a bowl and stir with a spatula until the dough comes together in small lumps.
• Tip it out onto the worktop, bring the dough together with your hands and knead it briefly until all the lumps have been worked into the dough.
• Divide the dough into 4 equal pieces. Roll each piece into a ball, press it lightly flat, make a hole in the centre and shape into bagels. Dampen your hands with a little water if needed – it makes the dough easier to work with.
• Place them on a sheet of baking paper, brush with beaten egg and sprinkle with sesame seeds, poppy seeds or bagel seasoning if you like. Bake in a preheated conventional oven (top and bottom heat) at 200°C for about 20-22 minutes – or until golden and baked through.
• Meanwhile, put all the ingredients for the tuna salad in a bowl and mix well. Season to taste with freshly squeezed lemon juice, salt and freshly ground pepper – and add a little more crème fraîche if you think it should be slightly creamier.
• Halve your bagels and let them cool slightly before filling them with tuna salad, avocado and rocket.