For the meat terrine, peel and finely dice the onion and garlic. Heat 1 tsp. oil in a frying pan. Sauté onion and garlic in it. Remove and allow to cool. Press the sausage meat from the skin into a large bowl.
Wash the chicken filet. Dab all meat dry and cut into small pieces. Add pistachios, onion and garlic to the meat and mix well. Season with salt and pepper.
Spread a box form (30 cm long; approx. 2 1⁄2 l contents) thinly with oil. Line the long sides with bacon so that they protrude over the edge of the mould to approx. 1⁄4 (see illustration on the right). Spread the meat mixture into the mould.
Fold over excess bacon. Bake in a preheated oven (electric cooker: 175 °C/circulating air: 150 °C/gas: see manufacturer) for approx. 1 1⁄4 hours.
For the cognac plums, bring 400 ml water, 1 teaspoon vegetable stock and plums to the boil and let it boil down for about 10 minutes while stirring until thick. Remove the pot from the heat, stir in the cognac and let it cool down.
Remove the terrine and let it cool in the mould for about 15 minutes. Drain the stock, carefully turn the terrine out of the mould and cut into slices. Serve with cognac plums. Fried potatoes taste good with it.
The terrine also tastes excellent cold.