Makes 1 10-12 inch wreath, Requires overnight refrigeration plus 2 hrs proofing time
Combine the milk and water in a small, microwave safe bowl. Heat in 30 second increments until lukewarm—no warmer than 110°F if you have a thermometer.
Add the warmed liquid to a large bowl of a stand mixer fitted with the dough hook attachment (or, a large bowl if you do not have a mixer), then sprinkle the yeast on top. Add 1 cup of flour, and mix until combined. Allow to rest and get slightly bubbly, about 15 minutes.
Add the remaining dough ingredients (including the rest of the flour) to the bowl and mix with a dough hook until smooth and elastic, around 8-10 minutes on medium-low speed. Alternatively, knead the dough by hand for 15-20 minutes.
Add the dough to a large, lightly oiled bowl and cover with plastic. Allow to rise for approximately 1 hour, until doubled.
Cover the bowl tightly and refrigerate the risen dough for 8-10 hours (overnight is ideal). It will continue to slowly rise and develop flavor over this time, and the chilled dough will be much easier to handle when shaping. Skipping this step is not recommended.
When ready to assemble the bread, combine both cheeses, the sundried tomatoes, and basil in a large bowl until well mixed.
Prepare a large sheetpan with a piece of parchment paper, and a small, oven-safe bowl placed in the middle. The diameter should be about 3-5 inches.
Roll the refrigerated dough into a 14x22 inch rectangle on a lightly floured surface. The dough will be very thin, but take care to avoid creating any holes. Spread the sundried tomato mixture evenly over the surface of the dough, leaving ½ inch of free space on both short sides, and 1 inch of free space on the long side edge that you are rolling toward. Tightly roll the dough along the long side edge, using the uncovered dough to create a seal once you reach the end. Rest the dough on the seam for 1-2 minutes to help it close.
Use a long, sharp knife to cut the rolled up dough in half, leaving 1 inch uncut at the top. Gently rotate each half of dough so that the cut side is facing up, then twist one strand over the other to create a two-stranded rope. Some filling will fall out in the process, but you can tuck it back in once the bread is shaped.
Once you create the long rope, wrap it, cut side up, around the oven-safe dish placed on your sheet pan to create a round wreath shape. The dish will help the dough stay spread out and not close in on the center once baked. Tuck and pinch the ends of the wreath together to seal, then cover lightly.
Allow the dough to rise until noticeably puffy, about 1 hour. In the meantime, preheat the oven to 400°F.
When the shaped loaf is risen, brush all over with egg wash, sprinkle with additional cheese if desired, then bake for 30-40 minutes, until deeply golden brown all over and a thermometer inserted into the center of the bread reads 200°F-210°F. If the bread is browning quickly but the internal temperature is not yet reached, you can drop the oven temperature to 350°F after 30 minutes for the remaining bake time needed.
Cool for 15 minutes on the pan before gently lifting the bread to remove the dish in the center. Cool completely before garnishing with basil in a bow shape, if desired, then serve.