Posted by ordo 
I'll risk it's the lack of salt (at the correct moment and in the correct proportion) what's killing your flavors.
Yes! +1.
In addition to under salting, it reads and sounds like you're doing lots of other things wrong. You need proportionally more onion and garlic, and less yellow squash. Yellow squash is watery and takes away more than it brings to the party. If you're going to use it, it needs to balanced by veg with more character.
Reading through the thread, your ingredients and technique make your dish sound watery and tasteless -- a lot more like weak soup than stew. If that recipe is for three people, it's far from generous.
You need to season the whole, bone-in, skin-on, chicken pieces well, then brown them, and remove it before browning, sauteing or softening the vegetables. You need to start with the aromatics -- onion, celery, carrot and garlic, before adding the potatoes and whatever else. You should add a little salt as soon as the onions soften. Some herbs should be sauteed before adding liquid; but by and large they're better in a bouquet garni or tea ball.
You're not getting nearly enough stock flavor from a single bullion cube. One cube is enough for one cup -- not 7/8 qt. Bullion cubes tend to be very salty and not very good; there are much better alternatives, like canned or boxed stock, or "Better than Bullion." If you want to use wine for your deglaze and as part of your broth, go ahead. I'd probably use some dry vermouth for its herbaceous flavor.
Note 1:
If you're looking for a full flavored stew, you're going to have to start with a full flavored stock. You're not using anywhere near enough chicken to get much flavor into the stew during what seems to be a relatively short cooking time.)
Taste the broth when it first comes to a simmer. Adjust for salt AND pepper. Use fresh ground pepper, pre-ground pepper goes stale and loses its taste quickly. If you don't like the idea of seeing black pepper in some foods, get TWO pepper mills -- one for white and one for black.
Simmer don't boil. If you can see boiling, you're cooking too fast.
You need to skim the scum off chicken stew at least a few times after the water comes to a simmer. Once you've got the scum out, you can taste and adjust for salt. Tasting and adjusting is one of the primary hallmarks of a good cook.
When the stew is done, remove the pieces of chicken. Discard the skin and bones. The bone should come out easily, and the chicken should be well enough cooked that you are able to chunk the meat with a fork or a spoon. Return the meat to the pot.
Generally:
What "seasonings" you choose depend on what you're trying to do. If you're looking for something French, you'll want to load up on thyme; Northern Europeanish -- tarragon and marjoram; Southwestern/Mexican -- chili powder or chilies in the cook, raw onions and dried oregano on the side; Italian -- rosemary and oregano.
Note 2:
When it comes to spices: Don't just use one thing, don't use too many, and use them in such a way that one taste dominates while the other.
Finally:
Your stew lacks interest and acid. Chop some fresh herbs and add them to your stew along with a goodly squeeze of lemon or lime juice immediately before service. Serve each dish of stew with a couple of lemon or lime wedges. Hot sauce wouldn't be a bad idea, either.
BDL
Edited by boar_d_laze - 9/9/12 at 12:46pm