Wash, halve and stone the plums. Put plums, 75 g sugar, lemon juice and 200 ml water in a pot and bring to the boil. Simmer at low heat for 4-6 minutes.
Mix starch and 2 tablespoons of water. Remove the pot from the heat and thicken the plums with the starch. Bring to the boil again while stirring. Separate the eggs for the semolina foam. Beat the egg white until stiff.
Bring milk, remaining sugar and salt to the boil. Add semolina while stirring, bring to the boil briefly and allow to swell for about 1 minute. Add egg yolk and stir in. Carefully fold in the beaten egg white. Pour the plum compote into an ovenproof dish and spread the semolina foam on top.
Bake in the preheated oven (electric oven: 200 °C/ gas: level 3) for 12-15 minutes. Roast the flaked almonds in a pan without fat until golden brown. Sprinkle over the semolina foam and serve warm.