Place the potatoes in a medium pot and cover, by 1 inch, with cold water.
Bring to a boil and simmer for about 5 minutes or until potatoes are tender. Drain.
Add 1 tablespoon of butter to a skillet over medium/high heat. Add the drained potatoes, sprinkle with the cumin and cook, stirring occasionally, for about 5 to 8 minutes or until slightly crispy and lightly browned around the edges.
Spoon the cooked potatoes into a bowl and set aside. Crumble the sausage into the skillet and cook over medium/high heat until sausage is evenly browned.
While the sausage is browning, begin working on the scrambled eggs. In a medium bowl, whisk the eggs, milk salt and pepper together until combined.
Melt 1 tablespoon of butter in a medium skillet over medium-low heat. Pour in the egg mixture and cook, stirring continuously till almost firm. Be careful to cook just until the eggs are set. Overcooking will give the eggs a rubbery texture.
To assemble, fill each tortilla with about 1/4 cup of eggs, 1/4 cup crispy potatoes, a spoonful of Chorizo sausage and sprinkle with cheddar cheese.
Top with a dollop of yogurt sauce and serve.