2. Heat the olive oil over medium heat in a skillet. Add the onion and cook for 5 minutes. Add the garlic, cook 2 minutes more and set aside to cool.
3. In a large mixing bowl, thoroughly combine the ketchup, egg, breadcrumbs, parsley, salt, pepper and the cooled onion mixture. Add the turkey and beef sirloin and mix until it is just combined.
4. Pack the mixture into a 9-inch loaf pan, brush the top with ketchup and bake for 1 hour until fully cooked. Let stand for 10 minutes before slicing.
For the potatoes:
1. Preheat the oven to 350°F.
2. Place the garlic cloves in an ovenproof dish and drizzle with olive oil. Place the dish, uncovered, in the oven for 15-20 minutes until the garlic is golden brown and soft. Remove from the oven and let cool.
3. Prick each potato several times with the tip of a sharp knife. Place them in a single layer in a microwave-safe container and microwave until they are tender throughout, about 8 to 10 minutes depending on the size of the potatoes.
4. In a small saucepan, bring the stock to a boil and turn down to a simmer.
5. Squeeze the roasted garlic cloves into a small bowl to release each clove of garlic. Mash the garlic with a fork and throw the skins away.
6. Mash the potatoes (and their skins) with a potato masher or fork. Add the roasted garlic. Slowly add the stock until the desired consistency is reached.
7. Season with salt and pepper to taste.