Preheat your oven to 350°F (175°C) to get things started.

In a large skillet over medium heat, brown the ground beef together with olive oil, the chopped red onion and garlic. Sprinkle with salt, pepper, and the flavorful Goya sazon seasoning. Cook until the beef is almost cooked through, ensuring a delightful medley of flavors.

Add the tomato paste and Worcestershire sauce to the skillet. Allow the tomato paste to brown alongside the beef, creating a rich and savory base for the Shepard's Pie. Stir well to combine all the ingredients.

Once the beef is fully cooked, set it aside to cool slightly while you move on to the next step. This brief intermission allows the flavors to mingle and intensify.

While the meat mixture cools, let the frozen mixed veggies thaw. This will ensure that they cook evenly and retain their vibrant colors.

Now it's time to assemble your masterpiece! Grab a pie plate and layer the ingredients in the following order: start with the meat mixture, then add a generous sprinkle of shredded cheddar cheese. Next, spread the thawed mixed veggies evenly over the cheese layer. Add another layer of cheese because, let's face it, you can never have too much cheese! Then, top it all off with a layer of creamy mashed potatoes, yet another sprinkle of cheese, and a dash of cracked black pepper for an extra kick.

Place your beautiful creation into the preheated oven and let it bake for approximately 30-35 minutes, or until it becomes hot, bubbly, and oh-so-melty. Your kitchen will soon be filled with a tantalizing aroma that will make everyone's mouths water in anticipation.

Once your Shepard's Pie has reached perfection, remove it from the oven and let it rest for at least 15 minutes. This short waiting period allows the flavors to settle and ensures that each bite will be an explosion of deliciousness.

Serve this comforting delight to your family and friends, and watch their faces light up with joy. This Shepard's Pie is perfect for cozy gatherings, potlucks, or any occasion that calls for a hearty and satisfying meal.