1. Prepare the Panade: In a large mixing bowl, combine the Panko breadcrumbs and the milk. Let it sit for 5 minutes. This mixture, called a panade, is the secret to moist, tender meatballs.
2. Combine Meatball Ingredients: To the panade, add the ground beef, beaten egg, grated Parmesan, garlic powder, onion powder, dried parsley, salt, and pepper.
3. Mix Gently: Using your hands, mix the ingredients together until they are just combined. Be careful not to overmix, as this can lead to tough meatballs.
4. Form the Meatballs: Roll the mixture into uniform balls, about 1.5 inches in diameter. You should get approximately 20-24 meatballs.
5. Sear for Flavor: In a large Dutch oven or heavy-bottomed pot, heat the 2 tablespoons of olive oil over medium-high heat. Working in batches to avoid crowding the pan, add the meatballs and sear them on all sides until a deep, golden-brown crust forms. This step is for flavor, not for cooking them through.
6. Set Aside: As the meatballs are browned, use a slotted spoon to remove them from the pot and set them aside on a plate. Do not wipe out the pot! Those browned bits on the bottom are pure flavor.

Stage 2: Build the Savory Stew Base

Now we use the flavorful remnants in the pot to build the stew.

1. Sauté the Aromatics: Reduce the heat to medium. Add the chopped yellow onion to the pot and cook, stirring occasionally, for 5-7 minutes, or until softened and translucent. Add the minced garlic and dried thyme and cook for another minute until fragrant.
2. Create the Roux: Sprinkle the all-purpose flour over the cooked onions. Stir constantly and cook for 1-2 minutes. This cooks out the raw flour taste and creates a roux, which will thicken the stew.
3. Deglaze the Pot: While stirring or whisking continuously, slowly pour in about 1 cup of the beef broth. Scrape the bottom of the pot with a wooden spoon to lift up all those delicious browned bits (the fond).
4. Add Remaining Liquids: Once the bottom of the pot is clean, gradually whisk in the remaining 3 cups of beef broth and the Worcestershire sauce until the mixture is smooth.

Stage 3: Simmer to Perfection

This is where the magic happens and all the flavors meld together.

1. Add Potatoes and Meatballs: Add the cubed potatoes to the pot. Gently return the seared meatballs (and any juices from the plate) to the pot as well.
2. Simmer: Bring the stew to a gentle simmer. Once simmering, reduce the heat to low, cover the pot, and let it cook for 25-30 minutes. The stew is ready for the next step when the potatoes are fork-tender (easily pierced with a fork).

Stage 4: Add the Creamy Finish

The final step that transforms this into a luxurious, creamy stew.

1. Stir in the Cream: Remove the pot from the heat. Slowly pour in the heavy cream, stirring gently to combine.
2. Season and Rest: Taste the stew and season with additional salt and pepper as needed. Let the stew sit for 5-10 minutes off the heat to allow the flavors to meld and the broth to thicken slightly more.
3. Garnish and Serve: Ladle the hot stew into bowls. Garnish generously with fresh chopped parsley before serving.