There are a few items that should always be in full stock in your kitchen ... well in my kitchen.
Onions
I don't really think there is much need for explanation other then onions simply make
everything better. Sauteing at the beginning adds a great flavor to kick off the meal.
Garlic
Garlic goes hand in hand with onions and adds depth to the meal. Caution should always be used however, because to much garlic can lead to issues later on.
Olive oil
A great many uses for this item. I don't think much explanation needs to be given when it
comes to the use of this except for the fact that it can be expensive and I tend to see
people use olive oil in situations when a cheaper oil can be used.
Vegetable oil
Vegetable oil is one substitute for olive oil that is at a cheaper cost. This is a better use if
frying food rather then olive oil.
Rice
Rice goes with any thing, in every culture. (period)
Tomato Paste
Sauces and soups are two very common and important components of a meal, and tomato
paste is very commonly used in both of them. By simply having a few small cans lying
around the house can bring your meal up to the next level.
Butter
I could go on for days about this ingredient, but I won't, so I will sum it up with one simple
thing. Three main ingredients in French cooking; 1. Butter 2. Butter 3. Butter.
Salt & Pepper
Probably one of the most basic ingredients around. As long as you are using Salt & Pepper
it's safe to say you are off to a good start. Remember though that it should be used with
caution. To much cannot necessarily be fixed, however not enough can typically be fixed
every time.
(dried) Oregano
Another simple ingredient that provides good flavor without any extra additives.
(dried) Basil
Same as Oregano. Though this ingredient is commonly used in both it's dry form and fresh
form. I put down dried simply cause it will last longer.
Flour
Flour is the base ingredient for so many things that I would be surprised not to see it in a
kitchen. Bread, noodles, sauces; so many things. Bread and noodles obviously require it
however sauces can be thickened with just a little flour to help attain that consistency that
you may have been looking for.
Eggs
Eggs, just like flour have a limitless amount of possibilities. A simple egg can be cooked so
many ways by itself. There are also so many types of meals: stir fry's, burger patties,
noodles, burgers themselves, appetizers, etc.
Everything else beyond these ingredients are typically best if bought fresh during the week or weekend before.
The main component of the dish is the chicken and sauce. 
This is one of those dishes that is reason to never walk down the frozen food section again. Home made pasta from start to finish in 45 minutes Max! The sauce was a spin off of a simple pomodoro sauce with the addition of a few extra things that happened to be in the kitchen. My cooking also leans on the factor of what is in my kitchen at the time. Not having much to some people can seem to be frustrating, because you feel like you need a lot to make something great. However fewer ingredients and the time to put them together properly can be just the boundaries you need to make something great. Mushrooms can add a great flavor to pasta dishes therefore starting off by sauteing them to release the flavor with the onions and garlic at the beginning is a good start. Then continuing with the typical ingredients to make your base sauce, tomato paste, salt & pepper, oregano, bay leaf, thyme and water you already have a great start. The last addition was a half glass of wine that just so happened to be in the kitchen already opened. Typically I don't like to open wine just to cook with it, unless I bought a small bottle, or it will be included with the meal. However left over wine from the day or days before should never be dumped out. It simply can be added to most any dish.