Combine 2 ½ cups strawberries, evaporated milk, nata and sugar in a blender. Blend until smooth. Transfer mixture to a freezer safe container and stir in remaining strawberries. Cover with plastic wrap and chill for 2 hours. Remove from freezer, scrape with a fork and return to freezer. Freeze overnight. To serve, thaw for 10 minutes, scrape with a fork and scoop into serving cups. Enjoy.