Fill a small saucepan with water up to three quarters. Add a good pinch of salt. This will prevent the eggs from cracking. Bring to a boil. Using a spoon, dip each egg in and out of the boiling water. To get the eggs hard-boiled, you need round 10 minutes. When done, remove from the heat and place in a bowl filled with cold water. When the eggs are chilled, peel off the shells. 

Make the dressing by mixing the soured cream, crushed garlic and Dijon mustard and season with salt and pepper.

Wash and drain the greens in a salad spinner or just by pat drying using a paper towel. Place the greens in a serving bowl and mix with the dressing. Halve, deseed, peel and slice the avocado and place on top of the greens.

Add the quartered eggs and season with more salt and pepper to taste.