Can you partially cook soup/stew and finish cooking it later?

Just to add a clearer answer to this question: in general, it is usually possible to partially cook a soup or stew one day and then finish it a day or two later. However, if one wishes to do so, there are some guidelines to keep in mind:

• Any perishable ingredients in the soup/stew should be thoroughly cooked, particularly things like raw meat, etc., which need to be cooked enough to destroy any residual bacteria
• The soup/stew should be cooled quickly (large pots should be broken up into smaller containers for more rapid chilling; and/or an ice bath can be used); it can then be stored for 2-3 days in the refrigerator or for longer times in the freezer
• The soup/stew should be reheated relatively quickly, getting above 140F as fast as is reasonable
• Once the soup/stew - including all ingredients in it - are above 140F, it can be simmered until the desired flavor and texture is reached

Comments have mentioned the option of cooking completely in advance and simply reheating. That's usually possible too, but there may be reasons to delay finishing some steps for a soup or stew until the final preparation. In particular, while flavors will generally meld together more during storage, any ingredients that are meant to taste more "fresh" should likely be added during the final cooking stage (e.g., fresh herbs, some vegetables or sauce elements meant to taste "fresh" and not overcooked). And some ingredients won't respond well to refrigerated storage (or to the freezer, if longer storage is desired), which could alter texture. For those who don't mind it if everything in the soup/stew is mushy, it's probably not a problem for most recipes. But to get more specific textures or levels of doneness for ingredients, it may be helpful to save some of the cooking until the final stage before serving.

And sometimes the reheating process itself may end up "overcooking" some ingredients, so it makes sense to wait and simmer upon reheating until the desired doneness.

I know the question asked about camping specifically, where many people don't worry about culinary details like this. But I thought I'd answer the question in general (and for those whose camping experiences may be more adventurous and finicky from a culinary perspective - I know mine sometimes are).