French Tuna Potato Salad (Paleo, Whole30)

Name: French Tuna Potato Salad (Paleo, Whole30)
Prep time: 15 min
Cook time: 20 min
Total time: 35 min
Cuisine: American
Ingredients: 3.5 lbs red potatoes; 25 ounces canned tuna (( Wild Planet is my favorite)); 1/2 cup diced white onion; 1/2 cup sliced scallions (including the green parts); 8 Tbs olive oil; 4 Tbs tarragon vinegar ((or apple cider vinegar)); 2 Tbs dijon mustard; 1 tsp sea salt; 3/4 tsp ground black pepper; 1/2 tsp herbes de provence; 3 Tbs diced fresh parsley