To make the Hollandaise:
Place egg yolks and egg in blender and blend on medium until it pales in color, about 30 seconds.
Add butter, lemon juice, Cajun seasoning, and cayenne pepper, and blend until smooth consistency, about 2 minutes.
To make the hash:
Preheat oven to 375 degrees F.
In large oven-proof skillet (I used my cast iron skillet) over medium-high heat, cook Andouille sausage until cooked through, about 7-10 minutes.
Remove from skillet and set aside.
In same skillet, add 2 tablespoons of olive oil over medium-high heat.
Add onions and peppers and cook 5-7 minutes, until they are becoming soft and translucent.
Add remaining 2 tablespoons of olive oil along with hash browns, Cajun seasoning, and salt.
Cook another 10 minutes, stirring often, to get hash browns crispy.
Return sausage to skillet and toss well to combine.
Make 4 indentations in hash, then crack one egg into each hole.
Place skillet in oven and bake 10-12 minutes, until egg whites are cooked and egg yolks are still runny.
Drizzle with hollandaise sauce.