You could do AFB in a dutch oven, but it would take at least two weeks of prepwork just to make the starter. Plus, if you're going to have dough rising overnight anyway I recommend making No-knead Pseudo Sourdough. It has a nice thick crust and a great, but subtle, sourdough taste without the hassle of starters. At the bottom of the linked post, it has directions for outdoor cooking in a dutch oven.
Edit: You could also check Mark's blog for an actual sourdough recipe cooked in a dutch oven.
I recently acquired The Scout's Outdoor Cookbook, and it has a fantastic recipe for "Hungry Hunter's Basic Bread." I've made it several times in the last month or two in both a 12" and a 10" dutch oven in my conventional oven. Here's the recipe, although I highly recommend getting the book:
If you're going to make this outdoors, I recommend mixing all the dry ingredients into a gallon-size zip-top bag while still at home. Don't forget to bring about two cup's worth of extra flour for kneading, or just in case the dough is too wet.
Note: Ingredient list is for a 12" DO)
8 cups all-purpose flour (6 cups for 10" DO)
3 tsp salt (2 tsp for 10")
5 tsp rapid-rise yeast (or two packets) (3 1/2 tsp for 10")
2 cups water, 120 to 130 deg. F (it's pretty darn hot!)
Mix dry ingredients in a large bowl. Add water. Stir until too stiff to mix, then knead by hand for 10 minutes. When finished, the dough should be soft and a bit sticky. Add small amounts of flour while kneading to adjust if the dough is too sticky.
Form dough into a smooth-skinned ball and place in a greased 12-inch dutch oven. It is important that the dutch oven isn't cold. Preheat, if required, but only enough to take the chill out of the metal. Turn dough over so the entire dough ball becomes oiled. Cover the oven and place two coals on lid near the edge.
Let dough rise until doubled in bulk, about 45-60 minutes depending on ambient temperature and wind conditions. During this time, keep the oven warm but not hot. The dough ball should fill the oven. Once the dough ball has risen, gently press it down to de-gas it. Remove the dough and carefully reform it into a smooth ball.
Return the dough ball to the warm oven, replace the lid, and replace the two coals with fresh coals. Allow the dough to rise again to about twice its bulk--about 30-45 minutes. It should now fill the oven nearly to the lid. Don't be tempted to add coals to hurry the process.
Once the dough has nearly reached the lid, place 11 fresh coals under the oven in a ring, just inside the edge of the base. Place 21 briquettes on the lid in a ring along the outer edge. Place two more coals in the middle of the lid near the handle. (For a 10" DO, use 9 under, 19 over + 2 in the middle.) Once you can smell the bread, it is almost finished baking. It should take about 35-45 minutes. Take a peek at 35 minutes to see if the top is browned.
Once the bread reaches an internal temperature of 185F it is finished; however, the top may not be as brown as you like. To brown the top, add up to 6 coals to the lid and bake another 5 to 10 minutes. Remove the bread and allow to cool on a rack for at least 45 minutes.
Slice and serve with copious amounts of butter.
This loaf was baked in a 12" dutch oven.