Seitan roast with grapes

For 4 people
500 g natural (whole piece) seitan
1 kg mixed (white and black)
1 sprig of rosemary
2 sage leaves
1 teaspoon oregano
1 clove of garlic
1 medium white onion
1 small carrot
1 stalk of celery
1 cup white wine
2 tablespoons tamari
100 ml extra virgin olive oil
salt

Peel and slice all the vegetables.
In a saucepan pour the oil, tamari, the smells, the carrot, celery and garlic.
Add seitan and, over medium heat, pour in the white wine.
Let Cook, stirring occasionally, for about 10 minutes, until the seitan is browned all over the surface.
Transfer to a baking sheet with a high edge and sprinkle with cooking liquid.
Set the oven to 180° and cook for 20 minutes.
Wash the grapes and draw out the berries.
After 20 minutes, add half the grapes into the pan and let it cook in the oven for a further 10 minutes at the same temperature.
Seitan is ready: transfer it on a cutting board and slice it.
Place in preheated serving dish, covering it with the cooking liquid and add the berries.