Heat the oven to 400°F. Lightly grease a 12-cup muffin tin. Set a large pot of salted water on the stove for the potatoes.
In a mixing bowl, combine the ground turkey, breadcrumbs, egg, chopped onion, 1 tablespoon of the ketchup, Worcestershire sauce, salt, and black pepper. Mix gently just until combined.
Divide the turkey mixture among 8 muffin cups, filling each cup evenly. Wrap one half-slice of bacon around the edge of each portion. Spread the remaining ketchup over the tops.
Bake the muffins for 25 to 30 minutes, until cooked through and the centers reach 165°F. Let them rest in the tin for 5 minutes before lifting them out.
While the muffins bake, add the potatoes and garlic cloves to the pot of salted water. Bring to a boil, then simmer for 15 to 20 minutes, until the potatoes are fork-tender. Drain well and return them to the warm pot.
Mash the potatoes and garlic with the butter and warmed milk until smooth. Serve the bacon-wrapped muffins with the garlic mashed potatoes.