Heat the milk and butter together until the butter has melted, but do not let it get boiling hot. That goes e.g., in the microwave. Stir in the sugar, salt and the egg. Crumble the yeast and stir in until it has completely dissolved. Finally, mix the flour and liquids together and knead until you have a smooth dough.
At this point you can add other desired ingredients. Grated cheese, for example, is great, but also poppy seeds, linseed, sesame or herbs.
Let the finished dough rise for at least 30 minutes. Then shape 5 balls of the same size and distribute them on the baking sheet. Make a hole and bake the bagels at 180 degrees for 20-25 minutes.