In a food processor, blend onions, carrots, and garlic until they form a rough paste. Add this into a large bowl with both meats, panko, worcestershire sauce, egg, salt, and pepper.
In a smaller bowl, combine tomato sauce, brown sugar, vinegar, and seasonings. Add 3 TB of this sauce to the large bowl with your meats and veggies.
Mix contents of large bowl until just combined and form into a loaf shape in a 13×9 pan. Your loaf should be about 12x5 inches.
Brush loaf with about half of the remaining sauce, then top with raw bacon strips. I criss-crossed them, but you can layer however you like.
Bake at 375 for 60 minutes, basting bacon with more sauce half way through. Broil for 30 seconds or so if you want more color on the bacon. It won't get super crispy, but the fat will render, and it will be very tender.
Cut into 8 even slices.