Place the eggs in a large saucepan and cover with water. Add a pinch of salt and bring to a boil. Cover and turn off the heat. Allow the eggs to sit in the hot water until cooked, about 12 minutes. Plunge them immediately into a bowl of ice water.
In a nonstick skillet, cook the bacon and leeks until both have crisped slightly. Drain on paper toweling.
In a small jar, place the vinegar, mustard, and spice mix. Place the lid and shake. Add the olive oil, replace the cap and shake again.
Place the lettuce in a large salad bowl. Toss with enough dressing to coat. Divide the dressed salad among four plates.
Peel the eggs and chop. Divide the turkey, ham, avocados, tomatoes, bacon-leek mixture, eggs, and blue cheese among each plate, placing each component in its own section of the lettuce bed. Serve with remaining dressing.
Make-ahead: The eggs, leeks, and dressing can be prepared in advance and stored separately in the refrigerator for up to 4 days.