1. Chop button mushrooms into very small cubes (brunoise), and sauté them with shallot and 1 teaspoon of butter.
2. Season with salt and peppercorn; set aside.
3. Combine the unsalted butter, and garlic in the bowl of a stand mixer and blend on low speed for 1 to 2 minutes until well combined.
4. Add into butter-garlic mixture, mushrooms mixture and all other ingredients, mixing just to well combine.
5.  Lay 2 large pieces of plastic wrap on a clean work surface; divide the butter evenly and place half at the center of each piece.
6. Use the wrap to help roll the butter into a sausage shape, keeping it tight and compact as you go.
7. Refrigerate or freeze inside a heavy-duty resealable plastic food storage bag until ready to use.

Note : The plastic-wrapped butter can be stored in a resealable plastic food storage freezer bag and frozen for up to 2 months. The “Snail” butter can be used for any number of dishes, including snails, mussels or clams cooked in their shells; over grilled steak or fish and also as a finishing touch for Risotto, soups and sauces.