Rotisserie Chicken Salad with Charred Scallion Dressing

Name: Rotisserie Chicken Salad with Charred Scallion Dressing
Ingredients: 5 ounces country-style bread, crusts removed, torn into 1-inch pieces; 10 tablespoons extra-virgin olive oil, divided; 2 scallions; Kosher salt, freshly ground pepper; 2 tablespoons fresh lemon juice; 2 tablespoons unseasoned rice vinegar; 1 tablespoon Dijon mustard; 1 tablespoon mayonnaise, preferably Hellmann’s (Best Foods); 1 small rotisserie chicken, meat pulled from bones and shredded; 6 radishes, trimmed, cut into wedges; 1 head of Bibb lettuce, leaves separated; 1 avocado, sliced, divided