Combine the flour, yeast and water, mixing until a rough dough forms.
Add the salt and a little oil, then knead until the dough is smooth and firm. Cover and leave to rise until doubled in volume (about two hours).
Divide the dough into 10 pieces weighing 80–90 g each. Form them into smooth, even balls, cover them, and leave them to rise again for one and a half to two hours.
Make a hole in the centre of each ball, gently shape the bagels, cover them, and leave them to rise for a further 30–60 minutes.
Bring a pot of water to the boil with two tablespoons of brown sugar, a pinch of salt and baking soda. Cook the bagels one at a time for one minute per side, then drain them gently.
Place them on a baking tray, brush the surface with beaten egg and sprinkle with sesame and poppy seeds.
Place the baking tray on the lowest shelf in a preheated, ventilated oven and bake at 220 °C for about 20 minutes, until evenly golden brown. Remove them from the oven and leave them to cool completely on a grill rack.
Stuff the bagels with a layer of mayonnaise mixed with yoghurt and lemon zest. Add the fresh lamb’s lettuce, Prosciutto di San Daniele, slices of buffalo mozzarella, confit cherry tomatoes and marinated courgettes.