Preheat a skillet or non-stick pan over medium heat.
Season both sides of the sirloin well with salt and pepper. Cook the steak on both sides to your desired temperature using a thermometer (see below). Once cooked, set aside to rest for 3-5 minutes before slicing thin against the grain.
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 6 minutes. Remove from the heat, drain the water, and run the eggs under cold water for 2-3 minutes to cool. Then peel and chop.
Lay down the lettuce, top with sliced steak, hard boiled eggs, avocado, cucumber, radish, tomato, onion, and blue cheese.
In a bowl, whisk together the Dijon mustard, garlic, lemon, and oil. Season with salt and pepper.
Dress the salad and serve with bread.