Chop the chestnut mushrooms, melt the butter and sauté the onion and garlic for 5 minutes. Add the mushrooms and thyme, and sauté for 8 minutes or until the mushrooms are cooked.
Reserving the juices in case you need to add a little moisture in step three, drain the onion/garlic/mushroom mixture, and blend it with the cream cheese and fromage frais.
Reserving some slivered almonds for garnish, process the nuts in the food processor then add them to the onion/garlic/mushroom mixture OR, if you prefer a finer, smoother paté, add the onion/garlic/mushroom to the food processor and process OR, for a more varied texture, process some of the onion/garlic/mushroom mixture with the nuts, then fold both mixtures together until they are well-combined. If the mixture becomes too dry (which is unlikely), add a little of the juice reserved in step two.
Chill the paté for 2 hours, then scatter the reserved slivered almonds on top and serve the paté with crusty bread, pita bread, crackers or vegetable sticks. This paté is best eaten within 2 days.
Chef's Note: Chestnut mushrooms are a closed cup mushroom with a wonderfully rich flavour. If you cannot find these, use flat field mushrooms which are always great, but may need a little more cooking.