Penne All'Arrabbiata(Milano, Italy)  
["500 grams penne or spaghetti (1 lb.)", "2 Tbsp. olive oil", "1 medium onion", "2 cloves garlic", "1 (14 oz.) can Italian plum tomatoes", "1 tsp. sugar", "salt and pepper", "1 small chili pepper or 1 tsp. dried crushed chilies (hot red pepper flakes)", "2 Tbsp. chopped parsley"]
["Heat the oil and gently fry the chopped onion and garlic until softened.", "Add the chili pepper and fry gently for 1 minute.", "Add the tomatoes with their juice, sugar, salt and pepper to taste and cook on a high flame, uncovered, for about 20 minutes, stirring occasionally.", "When the sauce is reduced and thick, check the season.", "If you like a smoother sauce, you can pass the sauce through the medium disk of a food mill.", "I usually just chop up the tomatoes with a fork and leave the sauce a bit chunky.", "Add the chopped parsley just before serving.", "Cook the pasta following the directions on the packet very carefully to avoid overcooking."]
["olive oil", "onion", "garlic", "Italian plum tomatoes", "sugar", "salt", "chili pepper", "parsley"]