Put cut potatoes in a large soup pot and cover with water. Don't peel the potatoes. Bring to boil over high heat. Then reduce heat to medium and allow to simmer for 20-25 minutes. Potatoes should pierce fork tender.
Preheat the oven to 425 F.
Place potatoes on a large, lightly greased baking sheet. Smash each potato with the base of a coffee mug until the potato is flattened. Each potato should be about 1/2 inch thick.
Drizzle potatoes with a bit of olive oil and sprinkle a generous amount of sea salt and pepper. Sprinkle on garlic powder and parmasaen cheese.
Bake potatoes for about 30 minutes. Cheese should be melted and potatoes should look crispy.
To make the avocado sauce, put avocado, lemon juice, mayonnaise, garlic, salt and pepper in a small food processor. Process until smooth.
Drizzle avocado sauce over crispy potatoes. Serve hot.