1. In a medium saucepan, bring three cups of water to a boil. Add a generous pinch of salt, stir in the Israeli couscous. Reduce heat to a simmer. Simmer until couscous is just tender, with a slight bite, about 10 to 13 minutes. Drain into a fine mesh strainer and set aside.
2. While the couscous is cooking, roast the asparagus. Preheat the oven to 400 degrees F. Place the asparagus spears on a large baking sheet and drizzle with olive oil and juice from 1/2 of one lemon. Season with salt and pepper, to taste. Roast for 10-12 minutes, or until spears are tender. Let spears cool and then cut into one-inch pieces.
3. In a large bowl, combine Israeli couscous, asparagus spears, artichoke hearts, and spinach. Squeeze lemon juice, from the remaining half and other lemon, over the salad. Stir well. Sprinkle salad with Parmesan cheese, if desired and season with salt and pepper, to taste. Serve.