CARAMELIZED ONIONS AND SWEET POTATO SALAD

Olive oil 3 red onions, thinly sliced 1 T. Dijon mustard ¼ c. balsamic vinegar 1 T. honey 1 T. finely chopped lemon or orange zest 1 T. finely chopped fresh thyme 2-4 sweet potatoes, sliced into ½” slices Canola…