Tex-Mex Au Gratin Potatoes ♥ Even the French would approve

When you marry into an Irish & English family, you better learn how to cook potatoes in 100 ways. Based on some minor sleuthing, I figure The Nudge ate potatoes in one way or another at least 5 days a week.

When I put a baked ham on the menu, in a matter of minutes I can predict I will hear "can we have au gratin potatoes with that?"

While white potatoes are on the "bad" list for a diabetic, omitting them from every one's diet is not a good thing.
I decided to see if I could bulk up on the diabetic friendly ingredients to tilt the dish in my favor without sacrificing the potato presence.

I made a list of ingredients that would pair well with potatoes and started cooking (turnip was added towards the end).
Tilted towards Tex-Mex foods with the addition of turnips, I added pepper jack to the traditional cheddar and I threw my first version into the oven.

Sometimes you hit a new recipe out of the ball park, sometimes you don't. This wasn't even a bunt.
While the flavor was good, the texture was horrible. Time for some research into the secrets of what makes a perfect potatoes au gratin.

Took me a few tries and a push in the right direction to get the right ratio but once I identified the problem the last batch was the final one. It wasn't the ingredients or the time in the oven it was the technique that was askew.
 
While most au gratins are made by simmering the potato slices in the cream, my first version turned out watery. The potatoes and turnips spent too much time in the cream sauce and could not absorb enough to create the consistency au gratin is loved for. Change the way ingredients are cooked before adding the cheese. That was the key to success.

My third try was perfection, and in my opinion easier. I remember watching America's Test Kitchen on PBS and many times making a potato dish, required microwaving first to remove liquid and optimize the starch molecules that were necessary to create a creamy texture in the potato before any cream was introduced. It was all about the food science.


A casserole or ramekins, your choice. I am all about the portion control so I made sure either was viable. The baking time was the same for both.

This was created for the last contest recipe but the cooking time fell well above the requirements for entries. Their loss, your gain.
No use deleting a good thing.

Let's get cooking.

Tex-Mex Au Gratin Potatoes
makes 6 servings

* 12 ounces canned or frozen corn
* 1 (6oz) can black beans, rinsed and drained
* 3 medium russet potatoes
* 1 medium white turnip 
* 1 cup heavy cream
* 1/2 cup milk
* 1 1/2 tablespoons flour
* 1 large clove garlic, pressed
* 1/4 teaspoon salt
* 1/8 teaspoon pepper
* 1 teaspoon chili powder
* 1 bay leaf
* 1 tablespoon butter, softened
* 4 ounces Pepper Jack cheese, grated
* 2 ounces sharp white cheddar cheese, grated

1. Preheat oven to 475°F and prepare a microwave and oven safe baking dish.
2. Peel and cut potatoes and turnip into 1/4" slices (I used a mandolin).
3. Beat together the cream, milk, flour, garlic, chili powder, bay leaf, salt & pepper until well combined. Pour mixture into a saucepan and warm over a medium heat while you slice the potatoes and grate the cheeses.
4. Coat the inside of a large microwave/oven safe baking dish or 6 (3/4 cup) ramekins with the softened butter. Mix the beans and corn with the slice potatoes and turnip.
5. Arrange the mixture evenly into the baking dish/ramekins.
6. Cover with wax paper and microwave for 10 minutes on high. Using a small knife or skewer inserted into potatoes to check for resistance. The knife should slide in with some resistance but the potatoes should not be hard. Microwave for 3 more minutes and test again. Once the knife slides in and out without help from you, remove them from the microwave.
7. Pour the cream mixture evenly over the potatoes and bake in a conventional oven until almost all the liquid is gone. Add the cheeses and bake another 10 minutes or until the cheese is melted and slightly browned. (I used the broiler right before serving)
8. Remove and allow to rest at least 10 minutes before serving.
Can be prepared up to two days in advance and reheated before serving.