Up to one week ahead: Order a large roasting chicken from your butcher (see recipe notes); you can order a kosher chicken from www.aaronsgourmet.com for $2.49 per pound plus shipping (be sure to indicate the size chicken you want when placing your order). Also shop for wine to serve with dinner.
Up to 3 days ahead: Hard-cook eggs for salad.
Up to 8 hours ahead: Set table; to decorate, group a few seasonal blossoms (we used Iceland poppies for their bright spring colors and elegant shapes) in small, matching vases for a simple, pretty centerpiece.
Up to 4 hours ahead: Make crumble.
2 1/2 hours ahead: Begin preparing chicken, potatoes, and shallots.
2 hours ahead: Toss asparagus with oil and seasonings; arrange in pan.
1 1/2 hours ahead: Roast chicken.
1 hour ahead: Assemble salad and make dressing; cover separately and chill.
20 minutes ahead: Roast asparagus.
10 minutes ahead: Dress and garnish salad.