Step 1In a small skillet, toast the coriander and fennel seeds over medium heat just until aromatic, 1 to 2 minutes. Be careful, as the seeds can over-toast and burn quickly; shake the pan or stir frequently to keep the seeds from burning. Remove from heat and set aside to cool.
Step 2In a large bowl, whisk together 4 cups of the all-purpose flour, the wheat flour, the yeast and toasted seeds.
Step 3In a medium bowl, or in the bowl of a stand mixer, beat together 4 eggs, the salt, one-half cup honey, the oil and 2 cups warm water. If mixing by hand, make a well in the center of the large bowl of dry ingredients and pour in the liquid mixture. Mix with a wooden spoon, slowly incorporating the dry into the wet ingredients until thoroughly incorporated. If using a stand mixer, with the mixer running, slowly rain the dry ingredients into the wet until thoroughly incorporated.
Step 4Slowly stir or beat in the remaining 2 cups all-purpose flour until thoroughly combined to form a sticky, wet dough. Transfer the dough to a well-floured work surface and continue to knead, adding extra flour as needed (up to 2 cups), until the dough is smooth and soft and only slightly sticky. Place the dough in an oiled bowl (turn the dough over so it is completely coated in oil), cover and set aside in a warm place until puffed and risen, about 1 hour.
Step 5While the dough is rising, heat the oven to 350 degrees. In a medium bowl, whisk together the remaining egg, 1 tablespoon honey and 1 teaspoon water to form an egg wash.
Step 6Assemble the challah: When the dough is risen, punch it down and set aside for 5 minutes, then divide the dough into 3 equal pieces. Carefully roll each piece into a long snake, oiling the pieces as needed to keep them from sticking. If you have trouble rolling one piece out (it may feel "tense" and bounce back when released), move on to the next piece, to give the first piece time to relax. Roll each piece to a length of about 2 feet. Braid the 3 pieces together, pressing together the ends of the braid so they do not unravel. Gently twist the challah into the shape of a circle, folding one end of the braid under the other to "tie," and pinching the ends so the circle does not come apart. Place the challah on a large, oiled baking sheet.
Step 7Brush the challah with the egg wash. Grease the outside of a small, oven-proof bowl (about 3 inches wide and 2 inches deep), and press the bowl down into the center of the circle. Brush the challah again with the egg wash, then sprinkle over the almonds.
Step 8Bake the challah until puffed and a rich golden-brown, about 45 minutes. Check the challah frequently as it bakes, brushing the seams in the braid periodically as they rise so they color with the rest of the challah, and rotating the challah once or twice to ensure even coloring. Shortly before it is done, check the challah once more and brush any light spots with the wash to add a little more color.
Step 9When the challah is done, remove it and cool the challah on a rack. Fill the bowl half-full with honey before serving.