I haven't cooked a moose roast, but I regularly eat elk and sometimes deer. I find with any wild, venison-type meat, you have to be careful about it drying out because it has a lot less fat than beef. You can season it similarly, but you will want to cook it at a lower temperature for a longer time or do it pot roast style (either in your oven or your slow cooker). I like to do a rub for my roasts with dry Keens mustard--no, really, it's good--cracked black pepper, and whatever seasonings fit my mood. The mustard forms a crust that helps seal the meat, and it does not taste mustardy at all when it is cooked.