Combine goat cheese and milk; stir well. Spread evenly over bread slices. Place bread on a baking sheet; broil 2 minutes or until toasted.
Combine spinach, fennel, and mushrooms in a large bowl. Combine vinegar and remaining 4 ingredients; stir well. Pour over salad; toss gently to coat. Place 2 cups salad on each of five plates; top each with 2 bread slices.