In a medium skillet over low heat, melt 4 tablespoons of butter.
Add chopped onion and garlic, cooking until the onion is wilted and transparent (about 5 minutes).
Add the ground pork, breaking it up and seasoning with salt and pepper, cooking until it loses its color.
Stir in the chopped mushroom stems and cook for an additional 3 minutes.
Remove from heat and mix in the bread crumbs, brandy, parsley, chopped pine nuts, and additional salt and pepper if needed.