To prepare the terrine:
In a small bowl mix the bread, 1/4 cup of cream, and the egg white.
In a large skillet, melt 2 tablespoons of butter over moderately low heat and use it to cook the garlic and onion. When the onion is softened, add the mushrooms. Cook and stir over moderate heat for about 5 minutes, or until the mushrooms have softened and have started to give off their own liquid.
Add 2 of the tablespoons of the Cognac and cook, stirring, until the liquid has reduced and evaporated.
Cool the mixture then transfer to a food processor. Puree it with the bread mixture.
Add the ground lean veal, the rest of the cream, and the salt and pepper to taste.
Blend the mixture, being sure to scrape the sides of the processor, until it is smooth. Transfer the mixture to a bowl and cover it. Keep it cool while cooking the mushrooms.
In the skillet, cleaned, melt 2 tablespoons butter over moderately low heat, and use it to cook the shallots in salt and pepper to taste. Continue cooking until the shallots are softened, then add the wild mushrooms and cook over moderate heat, stirring, for about 2 minutes.
Add the broth, wine, and remaining Cognac and boil, uncovered. Stir occasionally while the mixture boils, until all of the liquid has evaporated. Allow the mixture to cool, then stir it into the veal mixture.
Spoon into a well-buttered 1-quart terrine, smoothing the top.
Cover the terrine with buttered aluminum foil and a lid, then put the terrine in a baking pan. Add enough hot water to the baking pan to reach halfway up the sides of the terrine.
Bake the terrine in a preheated 350 F oven. Bake for about 1 1/4 hours, or until a meat thermometer registers 165 F. Permit the terrine to cool. Pour off any excess liquid. Invert the terrine onto a plate and chill it, covered, overnight.
For the coulis:
In a food processor, blend the roasted peppers, the oil, the vinegars, and the salt and black pepper to taste until the mixture is smooth.
Cut the terrine into 1/2 inch thick slices.
Pour about 1/4 cup of the coulis onto each of 8 serving plates.
Place a slice of terrine over the coulis. Sprinkle each serving with some of the diced bell peppers and chives.
To Roast the Peppers:
Using a long-handled fork, char the peppers over an open flame, turning almost constantly. Their skins should blacken in 2 to 3 minutes. Place the blackened peppers in a bowl and permit them to stand, covered, until they are cool enough to handle. Keeping the peppers whole, they should be peeled, starting at the blossom end. Cut off the tops. Discard the seeds and ribs.