Place mushrooms, stock and water in a sauce pot and heat, keep warm on low.
Heat a medium saute pan or risotto pan with 3 tablespoons extra-virgin olive oil, 3 turns of the pan, over medium to medium-high heat. Add onions and garlic to pan, season with salt and pepper, to taste, and saute until tender 4 to 5 minutes. Add pasta and toast until deeply golden in color and very nutty in fragrance, 6 to 7 minutes. Stir in wine and let it cook away, 1 minute. Ladle in stock every few minutes, stirring for a good minute with each addition of stock to develop starches. Evaporate almost all of the liquid before each addition of stock. Pasta will cook up quicker then rice. Start tasting after about 8 to 9 minutes of cooking time once you begin to add stock. When you are down to the last cup of your liquids, remove mushrooms, chop and add to pasta.
While the pasta cooks, toast hazelnuts in a skillet until fragrant. Peel nuts by rubbing the skins off in a clean kitchen towel.
When pasta is cooked to al dente, stir butter into the pan then stir in the cheese.
Dress arugula with lemon juice, a drizzle olive oil, and salt and pepper, to taste.
Serve risotto in shallow bowls topped with greens and nuts.
NOTE Oven Roasted Chicken Tenders Saltimbocca may be sliced and served atop or as a first or second course to meal.