Most recipes I’ve come across call for baking the raw potato slices in either plain liquid milk or a very thin béchamel sauce. Both methods work. With the plain milk, you need to use a moderately hot oven, no more than 350 degrees or the milk may separate. Curdling can happen in milk as the proteins coagulate and lump together. This causes separation of the curds (the protein lumps) from the remaining liquid. Several factors can cause curdling, including a high cooking temperature.
You can avoid curdling in scalloped potatoes in several ways. You could be sure to slice your potatoes thinly & evenly, don’t pile on too many layers, and bake in a moderate oven. You could bake the potato slices in a thin béchamel or white sauce. The added starch (flour or cornstarch) in the sauce will help prevent curdling. You can use cream for the liquid. Cream has more fat and less protein, so it doesn’t curdle. But no matter which of these methods you use, you still have to bake the potatoes in a moderate oven and that takes a while.
A few weeks ago I had a craving for scalloped potatoes, and it hit me at about 5:00 p.m. I knew that by the time I got the ingredients ready, put the casserole in the oven, and the potatoes actually cooked, we’d be eating too late. That’s when I remembered another method: cooking the potatoes in cream on the stove top first. I’d never wanted to try that method because I thought it was too much work, adding another step I didn’t want to follow. But I really, really wanted some scalloped potatoes. So I decided to give it a try.
I always have heavy cream on hand. That’s because I don’t tolerate fresh, liquid milk at all. I can handle yogurt, but no more than a ½ cup at a time per day. I have no problems with milk, yogurt, buttermilk, & sour cream in baking or cooked foods, thank goodness. For baking and any other recipes requiring milk, I use instant dry milk. I fix a little less than the recipe requires and then make up the difference with heavy cream. Because of its high fat content, heavy cream does not spoil as quickly as other milk products. It stays good in my fridge for quite a while.
I’ve found heavy cream useful in a low sodium diet. Just a couple of tablespoons added to a so-so gravy or sauce adds a sumptuous, rich texture that offsets blandness.
Back to scalloped potatoes: I didn’t want to use all cream for the potatoes, so I simmered them in low sodium chicken broth. I added two cloves of crushed garlic and some thyme to the simmering liquid along with thinly sliced onions. One time I uses frozen leeks from Trader Joe’s and low sodium vegetable broth. It didn’t take long before the starch from the potatoes had begun to thicken the sauce and the potatoes were slightly underdone. At that point, I stirred in about 1/3 cup of heavy cream, transferred everything to a greased casserole (made sure all the potatoes were covered in some sort of liquid), sprinkled with a combination of grated Swiss & cheddar cheese, and topped with homemade flavored bread crumbs (crushed garlic, 2 tablespoons Parmesan cheese, 2 tablespoons olive oil, and an assortment of dried & fresh herbs). I put the casserole in my pre-heated 400 degree toaster oven (425 degrees in a regular oven) and baked for about 15-20 minutes until bubbly and the potatoes were completely tender. If I had been thinking clearly, I would have used a stovetop-to-oven pan for simmering the potatoes. That would have saved one step and one dirty pan.
The entire operation, from start to finish, took about 30-35 minutes. Much shorter time than baking raw potato slices in the oven. I liked this method so much that I’ve used it several times since that first effort. The potatoes can be flavored many different ways: thyme, rosemary, or a special no-salt blend like Penzy’s “Mural of Flavor;” chopped jalapeno, poblano, chipotle, or Anaheim peppers; vegetable additions like carrots, sweet potatoes, broccoli florets, corn; and even homemade low sodium sausage crumbles or a couple of slices of crumbled low sodium bacon.
This method was much easier than expected and produced tender, creamy potatoes (with no curdling). My husband and I couldn’t stop nibbling. I really didn’t need anything else with the meal.