Preheat your oven to 425°F for roasting the vegetables.
Chop the carrot, red bell pepper, and zucchini into bite-sized pieces.
Place the vegetables in a bowl and drizzle with olive oil, a pinch of salt, and pepper. Toss to coat evenly.
Spread the vegetables on a baking sheet in a single layer and roast in the oven for 20-25 minutes, stirring halfway, until they are tender and lightly caramelized.
While the vegetables roast, heat a skillet over medium-high heat. Add the lean ground beef and season lightly with salt and pepper.
Sear the ground beef, breaking it up into small pieces, until it is cooked through, about 5-7 minutes.
Stir in the cooked white rice with the ground beef, allowing the flavors to meld for 2 minutes.
Once the vegetables are done roasting, add them to the skillet and gently toss everything together.
Adjust seasoning if needed and serve hot, enjoying the balanced mix of protein, grains, and roasted seasonal vegetables.