1. Place diced potatoes in a medium pot, cover with cold water, add 1 teaspoon salt, and bring to a boil. Reduce heat and simmer until tender, about 10 to 12 minutes. Drain and set aside.

2. Cook the bacon in a large skillet over medium heat until crispy, about 5 minutes. Transfer bacon to a paper towel-lined plate, leaving the fat in the skillet.

3. Preheat oven to 190°C (375°F).

4. In a large bowl, whisk together milk, beef broth, and egg. Add breadcrumbs, onion, feta, thyme, salt, and pepper. Mix until well combined.

5. Add ground meat and gently fold until just mixed. Do not overwork the meat.

6. Shape the mixture into meatballs about 3.8 cm (1.5 inches) in diameter. Place on a parchment-lined baking sheet.

7. Working in batches if necessary, brown the meatballs in the bacon fat over medium heat, turning to brown all sides, about 5 minutes total.

8. Transfer the skillet (if oven-safe) or the meatballs to a baking dish. Bake for 12 to 15 minutes, or until the meatballs are cooked through.

9. Serve the meatballs over the boiled potatoes and sprinkle with the reserved crispy bacon.