Peel etrog skin thin without the white pit as thin as possible, since the pit is bitter, and keep it as zest for towards the end. Etrog zest is quite bitter as well, therefore, boil up a pan hot water, place zest in a flat sieve (nafah)dip it very briely to the count of three ( 1,2,3) in the boiling water. Repeat this dipping two more times for a total of three times over in fresh boiling water each time. This will remove the bitternes from the zest.

Now for the main course. Weigh the etrog, take same amount of weight in sugar. Slice up etrog, not to thinly, so as making it easier to remove the seeds. Use amount of water like the volume of etrog slices. (place slices in milliliter cup, add water till it covers all slices to measure amount of water to start out with
(
Take measured water, place the prepared sugar, cook on low flame till suger dissolves, DO NOT MIX CONTENTS SINCE IT WILL CRYSTALIZE THE SUGAR. Once sugar is in solution, place all slices of etrog in sauce. Add one sliced lemon to the mix, for balance of flavor, having removed the seeds as well. Cook on low flame till you get RIBAH. This might take some time. As water evaporates, keep on replenishing water. It is tedious work removing the seeds and all, but it tastes like mmmmmm........, what Adam harishon felt before the chet.

Removing the seeds might be somewhat tricky. Place slice in bowl of water, press out seeds with a toothpick. Raise the slice against the light, to indentify them hiding inside the flesh. Repeat it twice to catch them all.

Take zest, place in a blender with just enough water to process it. Add this preferably at the end of cooking, so as to maximize aroma.

And Wallah a mechayeh. Vezeh kol hatorah kula.