Pour boiling water over the raisins and soak (for about 10 minutes). Rinse the pumpkin, peel it, grate the flesh on a coarse grater.
Measure 2 cups of grated pumpkin and place it in a larger bowl. Add grated onion, freshly ground pepper and nutmeg, mix.
Add mushrooms, olives cut in half, drained raisins, arugula. Season with freshly ground pepper and optionally salt. Drizzle with extra virgin olive oil.
Gently mix, sprinkle with crumbled ricotta cheese and serve immediately.
Instead of olive oil, you can drizzle the salad with honey vinaigrette (without garlic).