Preparation

Preheat the oven to 350°F. Slice the potatoes thinly on a mandoline or by hand. You need at least 16 slices. Brush each side with a total of 2 tablespoons of olive oil and lay on cookie sheets that have been oiled or lined with parchment paper. Make sure the slices are not overlapping. Bake for 10 minutes to soften. Remove them from the cookie sheets and let cool on a plate. It is okay to layer them. Meanwhile, cut the eggplant into 2" batons. Remove the stem and gills of the mushroom and slice into 8 slices. Mix together the remaining olive oil, the garlic, thyme, and a pinch of salt and pepper. Toss the eggplant, mushroom, and onion with the olive oil mixture and fold in the tomato halves. Spread out on a cookie sheet and roast for 10 to 15 minutes, until tender. Turn up the oven to 400°F. Lay two slices of potato side-by-side, overlapping by 1/4". Sprinkle with a pinch of salt and pepper. Lay a few pieces of eggplant, a slice of mushroom, and 5 tomato halves in the center. Fold the bottom edge of the potato over the filling and roll. Place on a cookie sheet. Repeat. Bake for 15 minutes, or until golden brown. Spoon Watercress Parsley Pesto, if desired, on a small serving plate and spread. If desired, place 1/4 cup of sautéed spinach over the pesto. Serve the rolls on top.