Make the dressing first so the flavors have time to meld: whisk together mayonnaise, Greek yogurt, honey, Dijon mustard, apple cider vinegar and garlic powder in a small bowl. Season with salt and pepper, taste and adjust. Chill in the fridge while you cook the turkey (about 10 minutes).
Heat a large skillet over medium-high heat and add 1 tablespoon oil. When hot, add the ground turkey and spread it into an even layer. Let it sear undisturbed 2 minutes, then start breaking it up with a spatula into bite-sized crumbles.
Continue cooking the turkey, stirring occasionally, until it’s well browned and some pieces have a little crisp edge (about 6–8 more minutes). Season with salt and pepper as it browns.
Push the turkey to one side of the pan and add the diced red onion; cook 2–3 minutes until softened. Stir the onion into the meat, then add ketchup, Worcestershire sauce, garlic powder and onion powder. Reduce heat to medium-low and simmer 1–2 minutes until the mixture is glossy and coated. Taste and adjust seasoning.
Turn off the heat and let the turkey rest in the pan for 4–5 minutes — this firms the meat so it sits nicely on the salad. If there’s excess liquid, drain it off or spoon the turkey out onto a paper‑lined plate.
Divide the chopped romaine among four bowls. Arrange the sliced red onion, cherry tomatoes, chopped pickles and shredded cheddar evenly over the lettuce.
Top each bowl with a quarter of the warm seasoned turkey, then add avocado slices. Drizzle the creamy honey‑mustard dressing over the salads (or serve on the side). Finish with a few grinds of black pepper and serve immediately.