How do I toast walnuts without burning them
Actually, I have two methods. If I'm not in a rush, I like to dry them out overnight in a very low oven - just turn your oven onto the lowest it goes, lay out some parchment paper on a baking sheet, and spread out the walnuts in a single layer. Check them every few hours to shake them up and make sure they're not burning.
If I want them toasted quickly, I like to do it on the stovetop rather than in the oven, so I can monitor their progress closely. I set a pan to medium heat and put the walnuts in it, stirring every now and then. They're ready when they start to smell fragrant and turn a deeper, darker brown. It can take surprisingly long for this to happen, but once it does, they can go from toasted to burnt in an instant, so be sure to not only take them off the heat, but remove them from the hot pan immediately.
I put them on a baking sheet in a preheated 350 degrees oven for 7 to 10 minutes. Let your nose tell you how toasted you want them.
Let your nose tell you, but be sure to set a kitchen timer for 7 minutes and start checking.
When I'm distracted by other things, I'll use a lower oven (225-ish) and just use my nose or check on them in about 10-15 minutes. The lower oven has helped a ton; I've burnt a lot of nuts in the past.