For a medium heat, use 3 chili peppers or use 6 chili peppers for a hot one. The method for preparation of the chilies is outlined above. Chop the onion finely and add it to a bowl with the lime juice and rind. The purpose of doing this is to soften the onion in readiness for adding to the salsa. Cut a small cross on the base of each tomato. Place the tomatoes into a heatproof bowl. Pour boiling hot water over the tomatoes and leave them to soak for 30 seconds. Remove the tomatoes and plunge them into a bowl of cold water. Drain well, then peel off the skins. Place the pieces into the salsa bowl.  Add this chopped cilantro to the salsa mixture.  Aim to coat everything with the lime juice. Place it into the refrigerator to chill and marinate for 2–3 hours. This will give the flavors time to blend well. Serve with tortillas, corn chips, beans or rice.

Summary:
Assemble the ingredients and items needed to make the salsa. Decide how hot you'd like the salsa to be. Prepare the tomatoes. Peel the tomatoes. Dice the peeled tomatoes. Add the soaked chopped onion and any lime juice and rind left. Chop the cilantro (fresh coriander) finely. Add the diced chili peppers and the sugar. Mix everything together gently until you see the sugar dissolve. Cover the salsa bowl. Before serving, throw a few lime rind pieces on top to garnish.