I'm currently trying to learn how to cook and my main problem are the lack of precise recipes. Most of them tell you what to do in very abstract steps but lack a way of verifying if what you do is right.
For example: When cooking polenta you have to mix the corn semolina into water. If you do it all at once the powder chunks but not one recipe I found tells you that.
Do you have a recommendation where too look for very verbose recipes?
For the beginner wanting explicit instructions, I don't think you can do better than a 14 day free trial of the America's Test Kitchen website. They break everything down to where it's almost foolproof (which can actually be a bit of a negative to highly experienced cooks); it's great if you're stepping outside of your comfort zone.
You can learn a LOT from that site in 14 days. Cancel within that window and you won't be charged. If you want one more month or simply to pay one month at a time instead of a 1 year lump payment, talk to customer service, they will accommodate.
Immediately upon free registration you will get access to some 14 or 15 seasons worth of videos, with accompanying recipes, taste tests and science lectures from the shows "America's Test Kitchen" and "Cook's Country", along with articles from the magazine, "Cook's Illustrated".
They're very highly regarded, and geared especially to help non-expert cooks not mess up.
This may sound a bit like a paid ad, but I assure you that it is not. My subscription paid up through the calendar year. I may or may not resubscribe, but I've totally gotten my money's worth so far.
EDIT I looked up your example. There are 2 recipes for basic stove-top polenta on the site. One says this:
... pour the cornmeal into the water in a very slow stream from a measuring cup, all the while whisking in a circular motion to prevent lumps.
and includes a 3 minute video straight from the television show demonstrating this recipe for polenta from beginning to end. In the video they cover the hows and whys of pouring the cornmeal in slowly while rapidly whisking in a circular motion and you see her actually doing that.
In the other recipe they use a wooden spoon.
very slowly pour the polenta into the boiling liquid while stirring constantly in a circular motion with a wooden spoon (see the illustration below).
They're like that with everything. If there is a way to screw up the recipe, they'll keep you from doing it. They'll also tell you what brands won their taste tests and their recommendations. I don't think for a second that they're willing to sell their influence. For polenta, they recommend:
internet recipes are often lacking, because generally all you get is the recipe itself. i've found that the best recipes come from cookbooks, which often have explanations and tips for many of their recipes.
of course, buying cookbooks requires an investment that beginning cooks might not be willing to make. but if you identify a well-respected cookbook for each cuisine you are interested in, you can often find what you need by googling the cookbook or author name, plus the name of the recipe you want to try.
for example, the benchmark italian cookbook is Essentials of Classic Italian Cooking by Marcella Hazan. if you google "hazan polenta," you'll find her recipe. it clearly addresses the issue you mention!
It is very rare that recipes are written with such detail. It is supposed that a cook's technique is sufficient for the recipe he or she attempts, and doesn't need to learn it from a recipe book. After all, a route planning application doesn't tell you to look left and right between crossing a street either.
It is preferrable to learn cooking techniques from books which teach techniques, and not search for such knowledge in recipe books, or even worse, internet recipes. But there is seldom a strict separation, because technique books almost always include recipes in order to teach the tecniques, and some recipe books for beginners are very verbose.
You should just page through a cookbook before buying it and see if it's right for you. It is very hard to judge a book just from online reviews, I have been disappointed more than once with books turning out to not be in a style suited for my intentions.
Here are a few points for quickly recognizing suitable books:
Note that there are exceptions to each of these points. For example, Death by chocolate is a book with very advanced techniques from a hard discipline, but it explains the technique anew in each recipe. There are also books which attempt to teach techniques, but are poorly written. Then there are very specialized books which teach an exact technique for a certain class of foods, Herme's macaron book is such an example. And lastly, there are long recipe descriptions which are sadly nothing but fluff. So take care to really look at the book, and don't despair if it doesn't work as well as expected.
