Preheat oven to 425 degrees F. Toss corn, potatoes, and red onion in a roasting pan. Drizzle with olive oil and season with salt and pepper. Roast vegetables for 15 minutes. Remove from oven, add the green beans and asparagus and toss with the other vegetables. Return vegetables to the oven and continue to roast another 15 minutes.
Vegetables are ready when potatoes are tender.
When ready to serve, toss roasted vegetables with enough Lemon Dill Asparagus Sauce to taste. Season to taste with additional salt, pepper, and fresh dill. Place salad greens on a large platter, top with roasted vegetables. Place lamb medallions around the edge of the vegetables with some of the greens showing. Garnish the vegetables with the olives, pine nuts, and feta cheese.