Bring a pot of water to a boil and gently add 3 large eggs; simmer 9–10 minutes for firm yolks.
Transfer eggs to an ice bath and cool 5 minutes; peel and quarter.
Wash and spin-dry 6 cups mixed lettuce; pat dry and tear into bite-sized pieces.
Slice 1 medium cucumber into thin half-moons or wedges.
Halve 1 cup cherry tomatoes and set aside.
Peel and julienne 1 large carrot into matchsticks for crunch.
Dice 1 cup cooked ham and 1 cup cooked turkey or chicken into small cubes.
Cube 1/2 cup cheddar and 1/2 cup Swiss cheese and place in a small bowl.
Arrange lettuce evenly on a large platter or four plates, creating a bed.
Neatly arrange cucumber, carrots, tomatoes and red onion in sections over lettuce.
Mound diced ham, turkey and cheeses in the center of the salad; add quartered eggs around the plate and sprinkle blue cheese crumbles if using.
Finish with a scattering of croutons if desired and drizzle dressing or serve dressing on the side. Season with freshly ground black pepper and serve immediately.