In a small bowl, mix together the low-fat cream cheese and finely chopped beet greens and thyme. Set aside.
Arrange the slices of bread on a baking sheet and toast under the broiler until lightly browned.
Spread about a teaspoon of the herbed cream cheese on a slice of toasted bread and top with a few slices of beets. Repeat for each piece of toasted bread.
Top each beet with a mustard green flower (if using).
Serve and enjoy!