Finely slice the pepper, zucchini, red cabbage and carrots. Prepare a large low bowl with warm water. Dip the rice paper rolls into the water until they soften, then remove and spread on a board. Lay spinach over the bottom third of the rice paper, flattening with your hand, then top with a little pepper, zucchini, carrot and red cabbage. Fold in the sides of the paper, tuck tightly and roll away from you until tightly closed. Repeat until all rolls are complete. Make the curry sauce by grinding the cashews, then mixing with the lemon juice, curry powder, turmeric and cayenne. Add enough water to your preferred consistency. Use this as a dipping sauce for your rolls.