Preheat your oven to 375°F. Roll out a sheet of puff pastry and place it on a baking sheet. Spread goat cheese over the pastry, leaving a border around the edges. Top with chopped asparagus and cherry tomatoes. Brush the edges of the pastry with beaten egg. Bake for 20-25 minutes, until the pastry is golden brown and the vegetables are tender. Serve hot or cold.