Preheat oven to 400 degrees. Bring a pot of salted water to a boil. Fill a large bowl with ice water. Wash and trim asparagus; peel all but the thinnest stalks. Drop asparagus into boiling water. Cook for 15 to 45 seconds, depending on thickness of stalks. Drain; plunge into ice water. When cool, drain again. Wash arugula; spin dry. Heat 2 tablespoons oil in a heavy-bottomed pan. Add garlic; cook until it turns golden. Quickly add beans, vinegar and salt and pepper to taste. Heat through; remove from heat. Add parsley. Using a fork or potato masher, coarsely mash beans. If needed, add salt and pepper to taste. Cover and keep warm. Toss blanched asparagus with 2 tablespoons oil and salt and pepper to taste. Place on a sheet pan; roast until lightly browned. Mustard seeds: Toast in a dry skillet and crush. Toss arugula with onion, remaining 2 tablespoons oil, mustard seeds and salt and pepper to taste. Toast bread in oven. To assemble sandwiches, top 6 slices of bread with bean mixture, then asparagus, then arugula-onion salad. Top with remaining slices of bread. Note: For best results, use cooked dried beans rather than canned. Instead of arugula, you can use other greens, like mache or even mesclun mix. VARIATION: with 6 tablespoons oil 493cals, 18g fat (31%cff). With 6 teaspoons olive oil 413 cals, 9g fat (19%cff). With commercial fat-free italian Salad dressing 378 cals, 5g fat (11% cff). SOURCE: March 27, 1999: "Asparagus makes for a tasty sandwich" By Dave Owens St Louis Post NOTES : sl postnet Recipe by: St Louis Post 1999 Posted to EAT-LF Digest by PatHanneman on Apr 09, 1999,