There is a hierarchy of importance when it comes to nutrition. Most importantly is the quality of the food you eat. Secondly, it matters how much food you eat. Thirdly it matters what the ratios of protein, carbohydrate, and fat you consume. Then way down at the fourth most important aspect of nutrition is what is known as nutrient timing.
The theory of nutrient timing places importance on the times you eat throughout the day and the post workout meal plays a key role in that schedule.
What is a post workout meal
Everyone should be eating meals throughout the day and in doing so a meal will most likely happen in the hours after your workout. That meal is not necessarily considered the "Post workout meal." The post workout meal is typically a larger meal consumed within 1 hour of hard training and is usually higher in carbohydrate than your other meals.
Does the post workout meal really matter
The post workout meal isn't really that important to most people. Nutrient timing is fourth down on the list of important aspects of nutrition, and should only be considered if the first three aspects are perfect.
Most people have a hard time eating the right foods in the correct quantities. Adding in some additional timing requirements to "eat properly" doesn't lead to success.
Your actual workout plays a role in whether a post workout meal would be beneficial. An extremely intense workout with heavy weight and fast movement leaves your body in a state that it can make better use of certain nutrients more than other times.
If your workout for the day is long with light weight, mostly cardio, or not very intense then your body is not ready to take advantage of a post workout meal. This means not every workout deserves a post workout meal. If you're wanting to experiment with post workout nutrition then you'll need to know your workout ahead of time and bring the meal with you if appropriate or at least have it ready to go when you get home.
What to eat
Without knowing your specific situation I can't tell you exactly what to eat but here are a few general guidelines you can use to start.
The meal should be fast absorbing. Since we're working in a limited window of time we want to choose foods that our body can digest and use within that 1-hour window.
The meal should consist of protein and carbohydrate only. Dietary fat actually slows down digestion so we want to keep that out of our 1-hour window.
These restrictions on what to eat limit our choices a little bit but it can be done. Here are a couple ideas but feel free to modify for your taste.
Non-Paleo Option - Whey Protein shakes made with orange juice and vanilla whey protein. Kind of tastes like an orange creamsicle. Whey protein is a quickly digested protein powder that meets our requirements, and orange juice is a dense quickly absorbed carbohydrate.
Paleo Option - A Chicken breast or two, and a blend of applesauce and sweet potato. This is a little slower to digest but if you get it in early within the hour window you'll be fine. Put a cooked sweet potato and some applesauce in a blender and blend it into something that looks like baby food. I've also added a little dash of cinnamon to this for some variation.
There is a lot of opinion and a little science in the conversation about post workout nutrition but the general consensus is that if your workout is hard enough that your body actually can make use of the additional carbohydrate then it can be beneficial but most people (including you) just need to focus on eating whole foods, in the right quantity to see 95% of the results that nutrition will offer.