Step 1

In a food processor, combine the cashews with the nutritional yeast and water and process to a fine paste. Transfer the paste to a bowl, stir in the olives and season with salt and pepper.

Step 2

Light a grill. Brush the eggplant slices (there should be about with olive oil and grill over moderately high heat, turning once, until tender and lightly charred, 2 to 3 minutes. Arrange the eggplant on a work surface and season with salt and pepper. Spoon 1 tablespoon of the cashew filling onto one end of each eggplant slice. Roll into tight cylinders. Cover with plastic wrap.

Step 3

Brush all of the vegetables with olive oil and season with salt and pepper. Grill the vegetables in batches until tender and lightly charred, about 3 minutes for the tomatoes and 6 minutes for the onions, peppers, eggplant and zucchini. Transfer the grilled tomatoes to a blender and puree until smooth.

Step 4

Peel, seed and dice the peppers and chop the onions. Add them to a large deep skillet along with the 2 tablespoons of oil and the garlic, bay leaf, thyme and oregano. Cook over moderately high heat until tender, 5 minutes. Add the wine and boil until evaporated, 2 minutes. Add the tomato puree and water, season with salt and pepper and simmer until the sauce is slightly reduced, 15 minutes. Cut the eggplant and zucchini into 1/2-inch pieces; add to the skillet. Simmer 10 minutes longer. Discard the bay leaf and stir in the basil.

Step 5

Spoon the ratatouille into shallow bowls and top with the involtini. Spoon a dollop of harissa on top and serve right away.