In a large skillet, heat butter over medium heat until melted and sizzling.
Add onion slices to skillet with a pinch of salt. Stir often and cook until tender and golden in colour, about 20 minutes. Remove from heat.
Preheat oven to 400 degrees F.
In a small saucepan, warm BBQ sauce, honey, and bourbon over low heat.
Place flatbread on a baking sheet and brush with the BBQ sauce mixture. Top with prosciutto, caramelized onions, and crumbled goat cheese.
Bake approximately 15 minutes, or until toppings are beginning to brown and flatbread is crispy.
If desired, warm the mango chutney in a microwave safe container or small saucepan and drizzle over finished flatbread before serving.
Cut into slices and enjoy.
