Prepare the Cuttlefish: Cut the cuttlefish into slices.
Sauté Cuttlefish: Put olive oil in a pan and transfer the cuttlefish. Sauté briefly.
Add Onions: Chop the onion and add it to the pan. Cut the spring onions into pieces and add them.
Deglaze and Simmer: Deglaze with the wine. Add the water and the vegetable cube. Bring to a boil, then cover, lower the heat, and simmer for 30 minutes.
Add Lettuce: Cut the lettuce into large pieces and add to the pot. Cover and cook for an additional 10 minutes.
Prepare Lemon Sauce: In a bowl, combine corn flour, zest and juice of two lemons, finely chopped dill, salt, and pepper. Mix well.
Finish the Fricassee: Transfer the lemon sauce mixture to the pot. Stir and cook for another 2 to 3 minutes until thickened.
Serve: Transfer to a plate. Add a drizzle of olive oil, freshly ground pepper, and a lemon slice for garnish and serve.