Tuna and White Bean Salad

INGREDIENTS

• 1 Tbs. plus 1/3 cup olive oil
• 2/3 cup fresh bread crumbs
• Salt, to taste, plus 1/4 tsp.
• Freshly ground pepper, to taste
• 1 garlic clove, minced
• Juice of 1 lemon
• 2 tsp. whole-grain mustard
• 1/4 cup coarsely chopped fresh flat-leaf parsley
• 1 can (15 oz.) white beans, drained and rinsed
• 2 celery stalks, chopped
• 1/2 small red onion, halved lengthwise and cut into slivers
• 2 cans (each 6 oz.) tuna packed in olive oil, drained and flaked
• 2 heads butter lettuce, pale inner leaves only