In a bowl, combine the blue cheese with the cream cheese. Set aside.
Preheat the barbecue or a griddle pan.
Place the burger on the griddle pan or barbecue and cook over medium heat for five to eight minutes or until cooked through.
In a second pan, over medium heat, cook the streak bacon until crispy.
In the meantime, in a second bowl, combine the cherry tomatoes, red onions, lemon juice, tarragon and salad leaves. Add a drizzle of olive oil and season well. Set aside until the burgers are cooked.
Toast the brioche buns.
Build the burger by placing the tomato relish on the brioche bun base, then the tomato salad, the burger, the bacon, a good dollop of blue cheese mixture. Finish with the top of the bun and serve immediately.
