Preheat oven to 400 degrees F.
Add the red potatoes, carrots, leek, shallot and garlic cloves to the Le Creuset garlic casserole dish. Mix the balsamic vinegar, olive oil and the vegetable broth and season with the kosher salt and vegetable broth. Add to the vegetable mixture and sprinkle with ¼ cup basil. Stir to combine.
Bake for 50 minutes to 1 hour or until carrots and potatoes are fork tender and lightly browned. At about 45 minutes and add the peas and a little more vegetable broth if the mixture has dried out, just do it doesn’t burn while continuing to cook.
Remove from oven and season with more kosher salt and pepper if desired and stir in additional ¼ cup basil leaves and chopped mint. Serve immediately or at room temperature.
** Cooking time will vary depending on size of your vegetables and oven temperature. I check the amount of liquid in the casserole half way through cooking to avoid burning.