Combine the goat cheese, parsley, thyme, and pepper in a bowl. Transfer the mixture to a pastry bag fitted with a small plain tip or sandwich bag with a small bit of the corner cut off.
Arrange half the beet slices on your work surface. Pipe a small amount of filling (about 1/2 teaspoon) onto the center of half of the beet slices leaving about 1/5-inch border around the edge.
Place another slice of beet on top and gently press down on the edges.
Garnish with thinly sliced beet greens tossed with a squeeze of lemon juice.
Serve and enjoy!