Place the eggs in a pot and cover with cold water. Bring the eggs to a boil on the stovetop. Once the water starts to boil, set a timer for 8 minutes. Remove from the heat, drain the water, and run the eggs under cold water for 5 minutes to cool. Then peel and quarter.
Season both sides of the sirloin well with salt and steak seasoning. Set aside.
For the dressing: whisk together all of the ingredients in a bowl until fully combined. Season with salt and pepper. Set aside.
Preheat a skillet or non-stick pan over medium heat. Once hot, cook the steak on both sides to your desired temperature using a thermometer (see below). (For thicker steak or for more well done finish cooking the steak in a 350 degree oven so the outside doesnt burn before the inside is done to your liking). Once cooked, set aside to rest for 3-5 minutes before slicing thin against the grain.
Lay down the lettuce, top with sliced steak, hard boiled eggs, avocado, tomato, onion, and blue cheese.