Memorial Day Potato Salad

I am going to a BBQ in a little while and am bringing a six pack of beer along with this variation on good old potato salad:

12 mixed color waxy potatoes (red, white and blue, actually!), cubed
1 medium Vidalia onion, diced
4 cloves garlic, minced
12 grape tomatoes, halved
1/3 cup extra virgin olive oil
1/3 cup tarragon vinegar
1/4 cup prepared mustard
sea salt to taste
black pepper to taste
2 tbsp dried tarragon
2 tbsp ground cumin
1 tbsp dried dill
2 tbsp ground turmeric

Brush the potatoes with oil, sprinkle with salt and roast until brown in a 400 degree oven. Transfer to a large mixing bowl and mix with the onion, tomato and garlic. Whisk the herbs, remaining olive oil, pepper, vinegar and mustard in a separate dish. Combine the vinaigrette and vegetables and stir thoroughly. Chill and allow at least two hours for flavors to combine.