For the onion tart, make shortcrust pastry with wholemeal spelt flour. Spread on 2 baking sheets.
Prick a few times with a fork. For the filling, cut the red onions and the smoked meat into pieces. Mix the sour cream with the eggs, salt and pepper.
Stir in the grated cheese, the smoked meat and the onion pieces. Spread on the shortcrust pastry and bake in the oven at 180°C for about 20 minutes.
Allow the onion tart to cool briefly and enjoy while still warm.