For the Sweet Tomato Relish: (make ahead)
1) Combine cherry tomatoes, red onion, garlic, red wine vinegar, brown sugar in a saucepan. Season with salt and pepper.
2) Simmer over medium heat until the tomatoes are soft and the mixture has a jam-like consistency, about 15-20 minutes. Allow to cool, then refrigerate until needed.
Relish can be made a day ahead. Bring relish to room temperature before assembling the burger.
For the Burgers:
1) Form the mixture into 8 patties, each about 3/4-inch thick and season both sides generously with salt and pepper. Make a small depression in the center of each patty to prevent it from doming up in the center.
2) Preheat your grill to medium-high heat and lightly oil the grate to prevent sticking. Grill the burgers for about 4-5 minutes on each side, or until they reach your preferred level of doneness.
3) While the burgers are grilling, spread a generous layer of the (room temperature) Triple Cream Cheese on each toasted brioche bun.
4) Once the burgers are cooked, let them rest for a few minutes, then place each patty on a bun, top with a generous spoonful of Sweet Tomato Relish, a handful of arugula, and finally, the top bun.
Serve immediately with a chilled glass of Domaine Carneros Brut Cuvée.