In a large stainless steel bowl, combine all of the vegetables, the olive oil, the sugar, and the garlic. Toss to combine.
Place a heavy-bottomed soup pot over very low heat.
Start sweating Lay the vegetables in an even layer in the pot. Evenly layer the chicken thighs over the vegetables, overlapping slightly if necessary.
Cover with a parchment lid (see below) and sweat for about an hour. Parchment lids help to retain just enough moisture in foods you're sweating or stove-top quick-braising. Plus, making one in front of guests Serves as a cool party trick.
The vegetables should be tender and almost translucent. If you've done this perfectly, some liquid will have rendered into the pan, and you'll have a juicy base on which to build the soup.
Simmer some more Add the water, stock, and saffron and simmer for another hour.
Using tongs, remove the chicken thighs to a cutting board and let them cool until you can safely handle. Remove and discard the bones, shred the meat by hand, and return the chicken to the pot.
Finish with salt, lemon zest, lemon juice, bitters, tomatoes and parsley. This soup base is perfect for freezing and subsequent "doctoring."
Step by Step: Making a Parchment Lid 1) Pull out a sheet of parchment paper a little wider than the container you're "lidding." 2) Fold the paper in half... 3) ...and again. 4) Fold across as to mock a paper airplane, being mindful to align the folded edges. 5) Fold the parchment over and over, until it becomes diffcult to create a seam. 6) Snip off the tip. This creates a little steam hole so the lid won't blow off a simmering pot. 7) Place the tip of the lid at the center point of the pot, then trim the far end so the lid will fit the pot exactly. 8) Unfold your lid. You'll know you folded it the wrong way if it ends up as two halves. 9) Place the lid in contact with the food you're cooking.