Given a paragraph about cooking, and a set of conversational question answers about the paragraph, generate a relevant question to the topic of the paragraph. The paragraph has the prefix 'CONTEXT:'. Each conversation question has a prefix `Q:` followed by the answer prefix `A:`.

CONTEXT: It is hard to tell from the picture, but this doesn't look like burned off seasoning, it is more like a burned on residue. If that's the case, you can try cleaning it some way. The problem is that physical cleaning methods probably won't be sufficient, chemical cleaning with alkali will damage the seasoning and chemical cleaning with acid, if the seasoning is compromised, can rust the pan a bit. So there is a high chance you will end up reseasoning. If this really looks and feels like a buildup and not like exposed oxidised metal, my preference would be to soak in warm, not hot, acid. Vinegar or a citric acid solution should work well. Afterwards, try to scrub off with a stiff plastic brush. If it doesn't go away, or the seasoning goes away too, or if this was missing seasoning from the beginning, you have to strip and reseason. We have several questions on the topic, and the Internet is also full of suggestions. I personally prefer doing it with lye (best results, strips both old seasoning and rust), owners of self-cleaning ovens like incinerating it, and there are a list of other methods to work with.  <sep>  Q: How do I recover from overheating my cast-iron skillet? A: It is hard to tell from the picture, but this doesn't look like burned off seasoning, it is more like a burned on residue  Q: What do I do if that is the case? A: If that's the case, you can try cleaning it some way  Q: What is the best cleaning method? A: The problem is that physical cleaning methods probably won't be sufficient, chemical cleaning with alkali will damage the seasoning  Q: What is best? A: my preference would be to soak in warm, not hot, acid. Vinegar or a citric acid solution should work well. Afterwards, try to scrub off with a stiff plastic brush  Q: What if this doesn't work? A: If it doesn't go away, or the seasoning goes away too, or if this was missing seasoning from the beginning, you have to strip and reseason 
How?

CONTEXT: The primary reason is definitely convenience. If you don't want skin and seeds in your sauce, then you have to do some work to avoid it. Yes, it's possible, e.g. passing through a food mill, or blanching and peeling plus retaining only the flesh, but having it already done is a whole lot easier.Passata is usually much thicker too, so it won't need as long a cooking time to reduce into a non-watery sauce as fresh tomatoes. On top of that, you don't have to worry about whether you can find good fresh tomatoes, e.g. if it's winter and they're out of season.Your two cases for comparison seem to overlook this: if you just chop and cook, you'll have skin and seeds in your sauce, as well as excess liquid to cook down, while if you use passata, you won't. (Also, for what it's worth, you'd need pretty giant tomatoes to get the equivalent of 3/4 cup of passata out of one tomato.)Of course, if you don't mind skin and seeds, it's also perfectly fine to simply cook fresh tomatoes and be done with it.Note that you can often get similar advantages from other canned tomato products. In the US, crushed tomatoes are far more common, and a roughly similar texture. (Peeled whole tomatoes, diced tomatoes, tomato sauce, and tomato paste can also be useful depending on what texture you're aiming for.)  <sep>  Q: What exactly is Passata? A: crushed tomatoes  Q: Is it better to use Passata instead of fresh tomatoes? A: The primary reason is definitely convenience 
Is the procedure that much more difficult to use fresh tomatoes instead of using Passata?

CONTEXT: Scallions are very touchy. You don't want them to dry out, and yet you don't want them too wet or they will get slimy and disgusting.What works best for me is remove any binding holding them together (e.g. rubber band or twisty-tie), (and certainly trim off any parts of the scallions that are already damaged and/or slimy), don't wash until you are ready to use them, wrap the bunch of scallions loosely (but completely covered) in a paper towel, and then store that wrapped bundle in a flimsy plastic bag (maybe the one you brought them home from the supermarket in) in your refrigerator. Sounds "fussy" when you lay out all the steps like that, but really, it's not a whole lot of work. Removing the rubber band etc. prevents damage where it would cut into the veg. flesh, paper towel absorbs condensation & liquid water which will rot the scallions (paper towel will prob. become slightly damp after a while in the fridge, but this is OK), plastic bag prevents evaporation of moist air.I find this works well for lots of greens, esp. cilantro - the worst offender in the demanding vegetables category.P.S. If you aren't too squeamish, you can even remove the very outermost layer of a scallion which has begun to "slime-out", wash the remainder right before using - & it's fine!  <sep>  Q: How do I preserve scallions? A: Scallions are very touchy. You don't want them to dry out, and yet you don't want them too wet or they will get slimy and disgusting 

Is there a good way to prevent the green part from drying out?