Preheat the oven to 200 °C.
Mix olive oil with lemon juice. Season with salt and pepper to taste.
Wash the pointed pepper, remove seeds and cut into long, wide pieces.
Mix pepper with lemon oil and place it in a baking pan. Bake about 15 minutes in the oven.
Drain tuna, mash with crème fraiche, salt and pepper.
Let the pepper cool down and place it on a plate. Fill with tuna cream.
Garnish with lemon slices and cress.