Sweet potato makes for a nutritious and satisfying substitute for pasta in this lasagna recipe. Even if your attitude about these sorts of things is “if it ain’t broke,” the odds are good that you’ll enjoy this alternative version. White sweet potato is mildly sweet and pleasantly earthy, making it more flavorful by far than your average noodle.
Like regular lasagna, this recipe takes time. However, it also keeps well, so it's a good dish to prepare ahead of time for a quick reheat on a busy weeknight.
- For the Sweet Potato Noodles:
- 12 ounces white sweet potato (peeled)
- Olive oil
- Salt and fresh ground pepper (to taste)
- For the Sauce:
- 2 tablespoons olive oil
- 1 medium yellow onion (small dice)
- 1 celery stalk (small dice)
- 1 medium carrot (small dice)
- 1 pound ground beef
- 2 cloves garlic (finely chopped)
- 2 tablespoons tomato paste
- 1 cup beef broth
- 1 splash white wine (optional)
- 1 tablespoon oregano (fresh, chopped)
- Salt and pepper
- For the Béchamel and Filling:
- 2 tablespoons butter
- 2 tablespoons flour
- 1 1/2 cups milk
- Salt and pepper
- Optional: 1 pinch nutmeg
- 6 ounces ricotta cheese
- 1 cup Parmesan cheese (grated)
Gather the ingredients. Preheat the oven to 350 F.
To make the "pasta," slice the sweet potatoes into thin flat strips reminiscent of sheets of pasta using a mandoline. Place the strips in a bowl, drizzle with a little olive oil and season with salt and pepper.
To make the sauce, heat two tablespoons of oil in a large skillet over medium heat. Add the onions, celery, and carrot. Sauté until slightly softened, about 5 minutes.
Add the ground beef. Cook, stirring occasionally and breaking up until browned, about 5 minutes.
Add the garlic and sauté for about 1-2 minutes more. Add the tomato paste, beef broth, wine (if using), and oregano. Stir to integrate the tomato paste. Season with salt and pepper.
Bring the sauce to a low boil then reduce the heat to a simmer, stirring occasionally.
Meanwhile, prepare the béchamel. Add the butter and flour to a small saucepan over medium heat. Whisk frequently as the butter melts. Cook for 2-3 minutes, stirring.
As you whisk, very slowly add the milk to the saucepan. Whisking constantly, bring the sauce to a boil, then reduce the heat to medium-low. Season with salt and pepper to taste. Continue to cook for about 3 more minutes until the sauce is a little thick like gravy. Remove from heat. If desired, add freshly-grated nutmeg to taste.
Reduce the red sauce further, if necessary, until the thickness of a fresh pasta sauce.
Build the lasagna in an 8 x 8-inch baking pan. Arrange the ingredients in layers, as follows: béchamel, sweet potato, red sauce, and ricotta and Parmesan. Repeat this sequence at least three times, saving some cheese for the top. Top with a layer of the sweet potato. Brush the top slices with a little more olive oil and top with the remainder of the cheese.
Bake for 45 to 60 minutes. To test for doneness, simply insert a butter knife into the lasagna. It should easily penetrate the layers (with the exception of the top layer, which will be a bit chewy and crispy).
Cool a few minutes and serve immediately.
- Store cooled leftovers in the refrigerator for up to one week or freeze in a sealed container for up to three months.a