Sift the flour and salt into a large mixing bowl, then add the yeast and mix well.
Measure 250ml/9fl oz warm water in a measuring jug and then stir in the honey and oil.
Make a well in the centre of the flour and pour the liquid in gradually, bringing the dough together with your hands.
Turn the dough out onto a clean, dry and floured work surface. Start kneading the dough, stretching it away with the palm of one hand and folding it back again with the other. Knead for approximately 10 minutes, adding more flour if the dough becomes too sticky. Continue kneading until the dough is firm and elastic.
Shape the dough into a large ball and place in a lightly oiled, large bowl. Turn the dough in the oil to coat. Cover with cling film or a plastic bag and put in a warm, dry place for 1–3 hours, or until the dough has doubled in size.
When the dough has proved, bring a large saucepan of water to the boil and add the treacle or molasses. Cover and turn off the heat.
Lightly oil two baking trays and sprinkle with polenta. Remove the dough from the bowl, then punch it down and knead it briefly. Roll it into a rough sausage shape and divide into seven equal chunks. As you work with one chunk, keep the others covered with a clean tea towel.
Firmly roll out each chunk into a long, slender sausage shape. Bring the ends together, splash the ends with a tiny bit of water and squeeze them together to seal. Place on the prepared baking trays and repeat with the remaining the dough.
Cover and set aside to prove for a further 10–20 minutes.
Preheat the oven to 220C/425F/Gas 7.
Bring the saucepan of molasses and water back to a gentle simmer. Gently drop each bagel into the water (do this in batches of no more than three at a time) and turn over after 1-2 minutes. Simmer for another 1-2 minutes, then remove the bagels from the water, and drain.
Place the bagels on the prepared baking trays, spacing them widely apart. Brush the tops with the beaten egg and sprinkle with sesame seeds, sea salt, poppy seeds or a savoury topping of your choice. Bake in the oven for 15 minutes, or until golden-brown, then turn them upside down for a further ten minutes to cook the bases. Transfer to a wire rack to cool before serving.