1. Heat a pan over low heat, add oil and flour. Stir constantly as oil heats up, so that the flour does not stick to the pan and form lumps. Then, gradually add cashew milk and stir constantly.
2. Leave the sauce for 10 minutes over low heat and stir from time to time, to prevent sticking. After simmering, add salt, pepper, nutmeg and stir. Before removing the sauce from heat, add grated plant-based Emmentaler.
3. Sprinkle olive oil over the bread and toast on each side. Put Bechamel sauce over one slice of bread, add 4 Mortadella slices, top with sliced plant-based Cheddar, and cover with the second slice of bread. Spread some Bechamel sauce over the entire surface and sprinkle grated plant-based Emmentaler.
4. Lay out the sandwiches on a parchment paper-lined baking pan and bake 5 minutes in the preheated oven at 180°C until lightly browned on top.
5. Serve the sandwiches with lettuce on the side.
