BLT Salad With Buttermilk Dressing

Name: BLT Salad With Buttermilk Dressing
Ingredients: For the dressing:; 1 1/2 teaspoons finely chopped shallots; 1 tablespoon lemon juice; 2 teaspoons white wine vinegar; 1/2 teaspoon salt, or to taste; 1/8 teaspoon freshly ground black pepper; 1/2 cup buttermilk; 1/4 cup mayonnaise; 2 tablespoons finely sliced chives; For the salad:; 6 slices thick-cut bacon, cut in half; 1/2 pound green beans, preferably haricots verts, ends trimmed; 1 teaspoon olive oil; 3 to 4 heirloom tomatoes of varying colors, sliced into thick rounds; 2 medium ripe avocadoes, sliced; Kernels from 2 medium ears of cooked corn (about 2 cups); Leaves from 1 head Boston lettuce, or salad greens of your choice