Preheat the oven to 400°F and line a large baking sheet with parchment paper.
Place the sliced zucchini, chopped red bell pepper, and red onion on the sheet, tossing with 1 tsp of olive oil, salt, and pepper.
Roast the vegetables for 20 minutes, or until they are tender and show beautiful caramelized edges.
While the vegetables roast, heat the remaining 1 tsp of olive oil in a large skillet over medium-high heat.
Add the ground beef to the skillet, breaking it into small crumbles with a wooden spoon until it is thoroughly browned.
Stir in the minced garlic, dried oregano, and tomato paste, cooking for 2 minutes to allow the flavors to deepen.
Remove the vegetables from the oven and fold them into the savory beef mixture before serving.