For the dumplings and salad:
Mix goat cheese
, mascarpone and chives in a bowl. Roll into small "dumplings" and set aside at room temperature.
For the Champagne Vinaigrette:
by mixing together vinegar, Champagne, vanilla, chives, salt, and pepper, in a small bowl. Add oil in a slow stream by whisking constantly.
Cut or shred
greens into 1/2-inch wide pieces. Combine cheese dumplings, greens
, and tomatoes and toss with enough vinaigrette to coat.