1. Heat butter in skillet over medium heat. Add leeks and mushrooms and cook, stirring occasionally, for 2-3 min, then add Madeira, salt and pepper, and cook, stirring, until moisture is evaporated and the mushrooms begin to brown, about 5 min.  Stir in herbs and transfer to a bowl to cool completely.
2. Transfer cooled mushroom mixture and goat cheese to a food processor and puree until combined. This can be as smooth or as chunky as desired.
3. Transfer to a bowl and roll into tablespoon sized balls. Arrange on a plate or baking sheet and chill in the freezer for about 15 min.
4. Make a dredging station by putting flour, egg and panko into three separate bowls. Remove balls from freezer and dip each one to coat in flour, followed by egg wash, and roll in panko.
5. Pour vegetable oil into skillet and heat over medium-high until oil shimmers but is not smoking. Working in batches, fry, turning often, until golden brown and crisp, 3-4 min.  Drain on paper towels and sprinkle with salt. Cool slightly before serving.

*To make vegan, replace butter with vegan butter or oil. Also replace eggs with vegan eggs.

Vegan goat cheese is not widely available but could be replaced with vegan cream cheese or vegan mozzarella