Mince chilies and garlic finely and place in a mortar. Mash with the heel of a cleaver or pestle. Add sugar and stir until it dissolves. Add fish sauce, vinegar and lemon juice, stirring between each addition. This makes enough for 2 to 4 people. I almost always double the recipe just to make sure there's enough. I've kept it for long periods of time but unless you freeze it, it's past it's prime after a few days. This is a basic chili sauce used for a dip for chicken or whatever. Variations of this are found in Cambodia, Thailand and other Southeast Asian countries. You can fiddle with it endlessly. This is a good starting point. The proportions shown here produce what I consider a mildly warm dip. I generally use two to six times as many chilies, depending on their strength and how hot I want it. Variations: use green serrano chilies instead of dried red ones, lime juice instead of the lemon juice or palm sugar instead of granulated. If you make it in a food processor, don't over process. It should have small chunks of each ingredient rather than being a homogeneous liquid. The taste is sour and hot, very puckery. It's great with poached or steamed chicken, duck or game hens. Much better with basically bland dishes rather than something like curry which has it's own blend of spices. Good with Chinese white-cut chicken or Steamed Ginger Chicken with Black Bean sauce. It's truly addictive and I often serve it with meals that are not Oriental in origin. Should be good with a firmfleshed white fish or boiled shrimp or crab. Fish sauce is a liquid made with anchovies and salt. It's not really fishy tasting. Look for it in the oriental section of supermarkets or at markets catering to Asian clientele. Tiparos is a good brand made in the Philippines. I prefer Thai or Vietnamese fish sauce, but they'll probably be harder to find. Chinese fish sauce is NOT a substitute.