Preheat the oven to 350°F.
While the oven is preheating, trim the ends from the eggplants, but do not peel them. Using a sharp-bladed mandoline or meat slicer (preferred) or a sharp knife, slice the eggplants lengthwise into uniform 1/8-inch think pieces. (The eggplant slices need to be thick enough to roll up.) You will need 24 slices plus two or three extra slices in case you need to piece together the last few cannelloni to make all of them of uniform size.
Arrange the slices in a single layer on rimmed baking sheets that are lined with parchment paper, or prepare in batches using only one baking sheet. Brush the slices generously on both sides with extra-virgin olive oil, using a total of about 1/2 cup of oil.
Season the slices on the top side with kosher salt and pepper, using a total of 1 teaspoon salt and 1 teaspoon pepper distributed among all the slices.
Bake the slices, uncovered, until noticeably softer and pliable, but not very brown, about seven minutes. Remove the slices from the oven and set them aside.
In a heavy 5 1/2 quart Dutch oven, heat 1 tablespoon olive oil over high heat until hot, about one minute. Add half the spinach and cook just until it wilts enough to make room for the remaining spinach, about one minute, tossing constantly with tongs. Add the remaining spinach and continue cooking just until all the spinach in the pan is wilted, one to two minutes more.
Let the spinach drain in a colander until cool enough to handle, about 30 minutes at room temperature, then wrap the spinach in a lint-free cloth napkin or dish towel (that you don't mind getting stained) and wring dry to extract all liquid possible. Coarsely chop the spinach and place it in a large mixing bowl.
Add to the bowl the ricotta, crabmeat, egg yolk, 1/2 teaspoon kosher salt and 1/2 teaspoon pepper. Stir fairly gently with a spoon to blend thoroughly, while keeping the crabmeat lumps intact as much as possible.
Line a rimmed baking sheet with parchment paper. Set Aside.
On a work surface, form 12 cannelloni as follows: Place one eggplant slice with the narrow (stem) end toward you. Leave enough space below this slice for a second one. Arrange a second eggplant slice below the first one, this time with the wide (bulb) end toward you and with the bottom slice overlapping the top one by 1/4 inch.
Spread 1/3 cup of the filling toward the wide end of the slice closer to you. Starting at the wide end where the filling is, roll up the eggplant slices loosely into a log shape measuring roughly 1 inch in diameter and 6 inches in length.
Place each log seam-side down in a single layer on the prepared baking sheet as formed. You may have to piece the last two or three logs with shorter lengths of eggplant so all the cannelloni will be about the same length. Once all 12 cannelloni are formed, cover and refrigerate them while you're preparing the sauce.
Once the sauce is finished, remove the cannelloni from the refrigerator, uncover and bake in the 350° oven until the filling is just heated through, 10 to 15 minutes. To test for doneness, insert the tip of a knife blade into the center of one of the cannelloni. If the tip of the blade feels hot, the cannelloni are ready.
Serving suggestions: For each main-course serving, use a spatula to transfer two cannelloni to each heated dinner plate. Stir the roasted-tomato butter sauce and spoon a portion (about 2/3 cup) over each serving of cannelloni. For each appetizer serving, use half these amounts.
Pass warm, crusty bread at the table.
roasted-tomato butter sauce
Serves: 6 as main-dish, 12 as appetizer
Reprinted with permission from ©Ralph O. Brennan, Ralph Brennan's New Orleans Seafood Cookbook, published by Vissi D'Arte Books click for book review
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