If it's hot outside you can bake these in your grill. Store them in the refrigerator for a few days and reheat at the same baking temperature. If you don't have a food processor to make the ricotta cheese you can use a high speed blender.
4large zucchinias straight as possible, ends trimmed
Using a madonlin or a knife, slice each zucchini into 1/4 inch (.635 cm) slices. You'll yield about 4 to 6 slices per zucchini, or up to 24 slices.
Brush each slice lightly with olive oil and sprinkle some salt on each side.
Grill the zucchini slices or pan-fry them on each side. Get them just soft enough to roll them but don't let them turn too soft or mushy.
Add the cashews, lemon juice, and salt to a food processor and process until smooth. Use a spatula to scrape down the sides in between processing. If you prefer the cheese a bit thinner, add water gradually until it's at the thickness you prefer.
At this point you can either add the spinach and basil to the ricotta cheese and process, or just chop the leaves up and mix them into the cheese with a spoon or spatula.
Spread about 1 tablespoon of ricotta cheese on each zucchini slice and then roll the slice up. Repeat for each zucchini slice.
Place the rolled zucchinis in a baking dish, add the tomato sauce on top of them and bake them for about 15 minutes at 400° F (200 C° or gas mark 6).