Preheat the oven to 425°F.
Wash and prep your vegetables by halving the radishes, peeling and slicing the onions into wedges, carrots into bite-sized pieces, and mincing the garlic.
Combine vegetables, oil, salt and pepper in a bowl and toss to combine.
Spread coated vegetables on a lined baking sheet in a single layer, turning radishes and carrots flat side down.
Roast vegetables for 15-20 minutes, then stir. Return to the oven for an additional 5-10 minutes.
Once the vegetables are fork-tender, move the pan to the topmost rack. Switch the oven to the broiler and broil the vegetables for 2-3 minutes until golden brown, watching carefully so they don’t burn.
Garnish with fresh herbs, sea salt, fresh cracked ground pepper, and a squeeze of lemon if desired.