Pre heat oven to 180 c / 355 f fan forced. Line a low sided, rimmed baking tray/sheet with baking paper & set aside.
Place breadcrumbs in a small bowl along with onion powder, garlic, ¼ teaspoon sage, thyme, marjoram & salt then mix lightly.
Add 2 tablespoon melted butter to breadcrumbs and mix to combine well, then add beaten egg and mix until well combined.
Place bacon rashers vertically on a clean work surface, then place one chicken thigh smooth side down on each rasher of bacon to form a cross or "+" shape.
Take ¼ of breadcrumb mixture and compress with your hands to form a rough oval shape patty, then place patty in the center of the chicken thigh - the patty will run the same direction as the bacon.
Bring up both sides of the chicken thigh to wrap around the patty, then bring up both ends of the bacon to cross over the top of the mini roast then secure each bacon end with a toothpick and place on prepared tray (see notes).
Using a pastry brush, brush the remaining 1 tablespoon melted butter evenly over the mini roasts, and bake for 30 - 35 mins or until cooked through & stuffing has crispy edges.
To make gravy, remove mini roasts from baking sheet/tray and keep warm, then carefully pour the remaining butter & pan drippings into a small saucepan, adding extra butter if needed & mix in the plain flour (see notes).
Stir butter & flour mixture over low heat until mixture starts to look grainy & bubbly.
Switch off the heat, then add stock in approximately ¼ cup amounts (stir well with each addition until there are no lumps before adding the next ¼ cup - once this mixture is the consistency of thin cream you can add the remaining stock.
Add a good pinch of powdered sage & simmer until gravy has thickened slightly, taste & season if required.
Remove toothpicks to serve if you wish, top with gravy & serve.