Mix the flour with the dry yeast. Whisk the egg in a large bowl with the salt and oil, then add the flour and stir together. Heat the milk with the sugar and stir gradually into the batter. Cover the dough and let rise in a warm place until it has doubled in volume (about 45 minutes).
Knead the dough into a roll on a floured surface and cut it into 12 equal pieces. Roll each piece of dough into a 15 cm (approximately 6 inches) long and about 4 cm thick (approximately 1 1/2 inches) strand. Form into rings, pinching ends together tightly, cover and let rise again for about 15 minutes.
Preheat the oven to 200°C (approximately 400°F).
Place the bagels in boiling water for about 1 minute, then remove with a slotted spoon. Drain and place on a greased baking sheet. Brush with the beaten egg yolk and sprinkle with poppy and sesame seeds.
Bake for 30-35 minutes in a preheated oven until golden brown.