Goat Cheese with Avocado, Celery, Walnut Pesto, and Watercress

This sandwich was inspired by a salad of avocado and celery that I grew up eating. The salad was dressed with lemon juice and olive oil; folks often add walnuts as well. So I've adapted these elements to a sandwich that balances the creaminess of the avocado with the crunch of the celery, the “high notes” of the lemon vinaigrette with the “bass note” of a walnut pesto. I added some watercress as well, to add some pepperiness. 
A great summertime sandwich, it’s easy to eat, both in the sense that it’s not at all messy and in the sense that while substantial, the sandwich is also light. 

Makes 4 Open-faced Sandwiches

8 tablespoons fresh goat cheese (chèvre)

8 slices hearty multigrain bread
1 cup sliced celery (about ¼ inch thick)
4 tablespoons Lemon Vinaigrette
2 cups watercress, largest stems removed
1 ripe avocado, halved, pitted, peeled, and sliced
Kosher salt and freshly ground black pepper
2 tablespoons Walnut Pesto

Spread the goat cheese evenly over 4 of the slices of bread. In a bowl, toss the celery in the vinaigrette, and place on top of the goat cheese. Add the watercress to the bowl used to dress the celery and toss with the remaining vinaigrette. Top the celery with the avocado, season with salt and pepper, and follow with the dressed watercress. Spread the pesto evenly over the 4 remaining bread slices. Close the sandwiches, cut into halves, and serve.