2# Red Potatoes – cubed with skin on
1# Sweet Potato – peeled & cubed
¼ Cup Red Wine Vinegar
1 Tbspn Spicy Brown Mustard
1- ¼ Tspn Kosher Salt
½ Tspn Fresh Ground Pepper
½ Cup Mayonnaise
¼ Cup Whole Milk
2 Celery Ribs – chopped
1 Small Red Onion – chopped
1/3 Cup Fresh Parsley – chopped

Place the red potatoes in a large pot and cover with water. Bring to a boil, then reduce the heat and cover, letting it simmer for 2 minutes. Add in the sweet potatoes, increase the heat and bring back to a boil. Reduce the heat, cover and let simmer for about 8 minutes, until the potatoes are tender.

In a mixing bowl, whisk the vinegar, mustard and salt & pepper together. Drain the potatoes and stir them gently into the mustard, vinegar mixture. Let this cool to at least room temperature.

In a separate mixing bowl, combine the mayo & milk. Stir in the celery, onion and parsley. Carefully stir this into the cooled potatoes, cover and refrigerate overnight before serving.