Preheat your oven to 350°F (175°C). Line a 9x5 inch loaf pan with parchment paper for easier removal, or lightly grease with olive oil.
Cook the quinoa. Rinse 1/4 cup quinoa under cold water. Combine with 1/2 cup water in a small saucepan. Bring to a boil, then reduce heat to low, cover, and simmer for about 15 minutes until the water is absorbed. Fluff with a fork and let cool.
Prepare the vegetables. In a small skillet, heat 1 tablespoon of olive oil over medium heat. Sauté the onion and bell pepper until softened, about 5 minutes. Add the garlic and cook for another 30 seconds. Let cool.
Combine all ingredients. In a large bowl, gently mix the ground meat, cooled quinoa, sautéed vegetables, eggs, feta cheese, sun-dried tomatoes, olives, remaining olive oil, all herbs, lemon zest, lemon juice, salt, pepper, and cumin. Mix with your hands just until combined—don't overmix.
Form your loaf. Transfer the mixture to the prepared loaf pan and shape into an even loaf, pressing down gently.
Make the topping. In a small bowl, whisk together the tomato paste, olive oil, honey or maple syrup, balsamic vinegar, and dried oregano until smooth.
Add the topping. Spread the tomato mixture evenly over the top of the meatloaf.
Bake covered. Cover the loaf pan with aluminum foil and bake for 40 minutes.
Finish uncovered. Remove the foil and continue baking for another 25-30 minutes, or until the internal temperature reaches 160°F (71°C) for beef/lamb or 165°F (74°C) for turkey.
Rest before slicing. Allow the meatloaf to rest for 10-15 minutes before slicing. This helps it hold together better.
Garnish and serve. Drizzle with a little extra olive oil and sprinkle with fresh herbs before serving. For a traditional Mediterranean touch, serve with a dollop of tzatziki or Greek yogurt on the side.