I need to roast some hazelnuts to use later for other preparations. How do you do it? In a cooking pan or in the oven, and for how much time?
While using a pan on the stove top can result in roasted hazelnuts (or any nut), it does require constant movement and attention. It can be quick, but it can also go wrong quickly if your heat is too high...or you stop shaking the pan for too long.
Alternately, roasting in a 325 to 350 F (163 to 177 C) oven, on a sheet pan, in a single layer, results in a much more predictable outcome and requires less direct attention.
Ten to 15 minutes would do the trick, but use your nose and eyes for guidance. Once nuts begin to roast, they can quickly go from perfect to burnt. Start checking after 8 or 9 minutes.
If you are working with hazelnuts that have the skins on them, after roasting, you can dump them onto a clean kitchen towel. Fold the sides over and rub the nuts between the towel. This should quickly remove most of the outer skins. I remove the cleaned ones to a bowl, and give the remaining ones another rubbing. You may have to work at (or ignore) the few stubborn ones.
Both the pan and the oven method work, use whichever you find more comfortable. If you don't yet know which is more comfortable, try both and see.
You can't predict the time, just roast until they smell good. If they are peeled, the color will turn slightly more golden. You will also recognize roasting too long (burning) by smell.
The one important thing that's not obvious to beginners is to have them in a single layer, do not fill the pan.
Microwave does pretty good job on this for me. The trick is to find the right power level and time. You'd need to find them by experimenting with the same amount of nuts. Once that is done, nuts can be roasted with no supervision.
I set power 5 out of 10 and time 5 minutes for about 200g of nuts evenly spread on a plate. The result is consitent and predictable.
I've had the habit of splitting the nuts in half and placing them split side up in the roasting tin. This seems to increase the flavour considerably. I do this with almonds as well (split lengthways along the thin edge). Obviously, I'm not catering for large numbers of people! I don't bother with removing the skin though, it's extra fibre after all. Also, I've been baking at 400° for a shorter period (about five minutes) but I'm going to try the lower temperature recommended above next time.