Asparagus Salad Nicoise

• 500 g 1 lb Ontario Asparagus, trimmed
• 500 ml 2 cups cooked cubed Ontario potatoes
• 250 ml 1 cup sliced Ontario mushrooms
• 170 g 1 can water-packed chunk tuna, drained
• 2 2 hard-cooked Ontario eggs, peeled and cut into wedges
• 1 1 Ontario greenhouse tomato, cut into wedges
• 8 8 oil cured olives

Dressing

• 75 ml 1/3 cup extra-virgin olive oil
• 25 ml 2 tbsp each white wine vinegar and water
• 1 1 clove garlic, minced
• 10 ml 2 tsp each dried tarragon and Dijon mustard
• 5 ml 1 tsp drained capers
• 1 ml 1/4 tsp salt
• 0.5 ml 1/8 tsp pepper