Preheat your oven to 400°F (200°C) and gather your ingredients.

Peel the carrots and cut them into uniform pieces, about 1-inch thick. Slice the red onions into wedges and the fennel into thin strips.

In a large mixing bowl, toss together the cut carrots, red onions, and fennel with olive oil, adding salt and pepper.

Spread the vegetable mixture in a single layer on a large baking sheet.

Roast the vegetables for 25-30 minutes, tossing halfway through for even cooking.

Allow the roasted vegetables to cool for at least one hour.

Before serving, toss the cooled roasted vegetables with freshly chopped mint.