1 Wash and core the apples; cut into eighths. Transfer to a saucepan and add 4 tablespoons water, honey and cinnamon. Bring to a boil, then reduce heat and cook for 4-5 minutes.
2 Meanwhile slit the vanilla pod with a sharp knife and scrape out the seeds. Transfer vanilla seeds to a pan; add milk and salt. Bring to a boil.
3 In batches gradually whisk semolina and sugar into milk. Whisk until mixture comes to a boil again. Remove the pan from heat; cover, and let steam for 4 minutes.
4 Meanwhile chop the walnuts. Stir the semolina well and pour into bowls. Serve topped with apples and walnuts. Sprinkle with lemon balm leaves, if desired.