Season duck legs with salt. In a large stock pot, heat olive oil over medium heat. Sear duck on all sides for about 10 minutes. Remove duck from pan and pot aside.
Add onions to the pot. Cook for 3 minutes, and then add garlic, celery, and carrots. Cook for another 2 minutes. Add tomato paste and cook for an additional 30 seconds.
Return duck legs to pot. Add thyme, bay leaves, sugar, red wine, and tomatoes to the pot. Bring to a boil. Reduce heat and simmer for 2 hours. Skim any fat from the sauce.
Carefully remove the duck legs from the pot. Discard the skin, fat, and bones. Shred the meat and return to the pot. This sauce can be made 1-2 days in advance.
At Camp...
Light briquettes.
Bring a large pot of salted water to a boil on a campfire or camp stove. Cook noodles until soft, about 8 minutes.
While the noodles cook, mix together the ingredients for the ricotta filling.
Drain noodles. While the noodles are still warm, lay them flat on a clean work surface. Spread three tablespoons of ricotta filled to each noodle and then roll.
Add 1 cup of the duck ragu to the bottom of greased Dutch oven. Place rolls with end vertically. Divide fresh mozzarella into even pieces and snuggle in between rolls. Top with additional ragu.
Placed 18 briquettes on top of Dutch oven and six on the bottom. Cook for 30-35 minutes. Garnish with fresh basil.