Wash the tomatoes and cut them in half crosswise. Place the halves - open side up - on a cookie sheet. In a small bowl, mash together the avocado (sludge), grated Swiss cheese (pus), and basil (poisonous plant matter). Spoon the mixture on top of the tomatoes and sprinkle with oregano (fly wings). Broil the tomatoes for 5 minutes, or until pus begins to ooze. Carefully remove the tomatoes from the broiler and serve hot, or allow to cool slightly and eat them with your hands (wearing plastic gloves, of course - to keep from being contaminated)!