PREHEAT oven to 425°F. COMBINE goat cheese, 1 tbsp. parsley, chives, dill, garlic and lemon zest until smooth and spreadable.
PLACE pastry on lightly floured surface. ROLL into 9-inch square. CUT into 4 even portions. SCORE 1/2-inch border on all sides of pastry squares with sharp knife. PRICK pastry all over inside score lines with fork. PLACE on large parchment paper–lined baking sheet. TRANSFER to freezer for 5 minutes.
BEAT 1 egg with 1 tbsp. water; set aside. SPREAD goat cheese mixture evenly inside score lines of each pastry square. BRUSH border of each pastry with egg wash.
BAKE for 12 to 15 minutes or until pastry is lightly golden. REMOVE baking sheet from oven. CRACK egg into center of each pastry. TOP evenly with tomato slices. RETURN to oven; bake for 8 to 10 minutes or until whites are set and eggs are cooked to desired doneness. SEASON with salt and pepper. GARNISH with remaining parsley.
Substitute tarragon or basil for dill if desired.
Alternatively, use store-bought herbed goat cheese or your favorite flavored goat cheese for a quick substitution.