Clean the savoy cabbage and blanch in boiling water. Remove the leaves from the stalk and allow to drain. Leave the bacon in a pan without fat until crispy. Drain on kitchen paper and break into large pieces, put something aside for garnishing.
Melt the fat in a pot. Dust with flour and sweat it. While stirring, deglaze with broth and milk. Bring to the boil. Stir in mustard and season with salt. Wash the salmon, dab dry and cut into thin slices.
Wrap a springform pan (26 cm Ø) firmly into aluminium foil from the outside. Grease the mould. Spread a thin layer of sauce on the bottom. If necessary, break the lasagne sheets into the form and lay 1 layer on the sauce. Layer all prepared ingredients on top (sauce, savoy cabbage, sauce, noodles, salmon, sauce, pasta, savoy cabbage, noodles, bacon, sauce).
Grate cheese and sprinkle lasagne evenly with it. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 45 minutes until golden brown. Garnish with remaining bacon, cherry tomatoes and savoy cabbage.