Rich and Sweet by Bia Rich: Leek and Asparagus Soup with Spicy Croutons...  2 tbsps olive oil;  1 shallot, chopped;  3 leeks, white and light green parts only, sliced;  2 bunches asparagus, ends discarded and cut into 2 inch pieces;  6 cups vegetable stock;  salt and pepper to taste;  truffle oil to garnish...  spicy croutons:  4 slices thick french bread, cubed;  oil spray;  1/2 tsp cayenne pepper;  1/2 tsp fresh black pepper.