In a small bowl, combine the olive oil, vinegar, juice, zest, honey, mustard, tarragon, parsley, salt, and pepper.
Set aside.

Heat grill or grill pan to medium high.  Using a brush, lightly coat the bread and onion slices with olive oil.  Season with salt and pepper.  Place the onion slices on the grill.  Cover and cook until charred, about 4 minutes, then flip and cook, covered, for another 2-3 minutes.  Set aside.  Grill the bread for 3 minutes or until toasted.  Flip and grill another minute.  Set aside.  Roughly chop the grilled onions and the bread into 1” square pieces. 

In a large bowl, combine the onions, bread, salt, pepper, grapes, radicchio, cucumber, and pistachios.  Add the salad dressing and gently toss to combine.  Divide the salad into 6 equal servings and top each with goat cheese.