Put carrots in a large, deep skillet and barely cover with water. Season with a pinch of salt. Cook over medium-high heat until the carrots begin to soften, 10–12 minutes.
Remove the carrots and set aside, reserving the cooking liquid in the skillet. To the liquid, add the orange juice, lemon juice, cumin, and pepper. Smash a garlic clove, discard the peel, and add to the cooking liquid. Bring to a simmer and reduce until syrupy, 10 minutes. Meanwhile, when the carrots are cool enough to handle, cut into rustic chunks and set aside in a bowl.
Remove syrupy mixture from heat and add olive oil; shake it around in the skillet to create a vinaigrette. Discard the garlic and spoon the vinaigrette over the carrots. Garnish with torn mint and cilantro. Toss and serve.