How to Make It
Light a grill or preheat a grill pan. Brush the asparagus with oil and season with salt and pepper. Grill over high heat, turning, until tender, about 5 minutes. Let cool, then cut the asparagus into 1-inch pieces.
In a large bowl, toss the mesclun with the grilled asparagus, cucumber, tomatoes, chickpeas, olives and cheese.
In a bowl, whisk the orange juice, lemon juice, vinegar, both mustards and a pinch of salt and pepper. Gradually whisk in the 1/2 cup of oil until emulsified; add the tarragon. Pour the dressing over the salad and toss. Garnish with pita chips and serve.