Make the ranch dressing: In a small bowl, whisk together the mayo, yogurt, milk, and lemon juice until smooth. Add the dill, parsley, onion powder, garlic powder, salt, and pepper, and whisk until combined. Cover and refrigerate until you’re ready to use it. It will keep, stored in the refrigerator for up to a week. If you need to thin it out any further, start by adding a teaspoon of skim milk (or water) and stir, adding more as needed.

Preheat your oven to 400° F. Line a large rimmed baking sheet with aluminum foil. Arrange the slices of bacon on the baking sheet. Bake until crisp, 15 to 20 minutes, depending on how you like your bacon. Transfer the cooked bacon to a paper towel-lined plate.

Season the chicken breast tenderloins with salt and pepper. In a large nonstick skillet, heat the olive oil over medium-high heat. Once hot, add the tenderloins and cook, turning occasionally to brown all sides, until cooked through, 8 to 10 minutes. Remove the skillet from heat, add the barbecue sauce, and toss the tenderloins to coat them. Transfer to a cutting board and let cool for 5 minutes. Chop into 1-inch pieces.

In a large bowl, toss the chopped romaine, carrots, cucumber, corn, and black beans. Divide the salad among 4 bowls or plates. Crumble the bacon and distribute it evenly over the salads, along with the chicken, avocado slices, and fried onion strings. Drizzle each salad with 2 tablespoons of dressing and serve.