My great grandmother used this simple 4 ingredient trick to stretch a dollar. We make it every Mother's Day to honor her and the kids always beg for second helpings.

This slow cooker 4-ingredient depression era onion spaghetti is my modern take on the kind of dish my great grandmother leaned on when money was tight but she still needed to feed a crowd. It’s built on pantry basics: onions, dry spaghetti, butter, and a bit of broth or water with salt to stand in for the seasoned cooking liquid she would have used. Long, slow cooking coaxes deep sweetness out of the onions, which then melt into the pasta and butter to create a glossy, savory-sweet sauce. We make it every Mother’s Day to honor those resourceful women who knew how to stretch a dollar, and the kids always ask for seconds because it tastes like pure comfort in a bowl.

Serve this onion spaghetti in warm shallow bowls with plenty of the buttery onion strands spooned over the top. A simple green salad with a bright vinaigrette or sliced fresh tomatoes with a pinch of salt help balance the richness. If you’d like to keep the spirit of thrift, pair it with crusty bread or toast made from day-old bread to mop up the glossy sauce. A light, crisp white wine or sparkling water with lemon works nicely alongside, but this is just as at home with a glass of milk for a very old-fashioned, family-style supper.

Servings: 4

4 tablespoons unsalted butter, divided

Lightly grease the inside of a medium slow cooker (3–4 quart) with 1 tablespoon of the butter to help prevent sticking.

Peel and thinly slice the onions from root to tip so you get long, even slivers. This shape lets them tangle nicely with the spaghetti once cooked.

Add the sliced onions to the slow cooker and dot with 2 tablespoons of butter. Pour in 1 cup of the broth (or salted water), then stir to coat the onions evenly.

Cover and cook the onions on HIGH for 3 hours, stirring once or twice if you can, until they are very soft, golden, and starting to caramelize around the edges. They should be jammy and sweet, sitting in a shallow pool of flavorful liquid.

Break the dry spaghetti in half so it fits more easily in the slow cooker. Nestle the spaghetti into the onions, spreading and pushing the strands down so they are as submerged as possible in the onion mixture.

Pour the remaining 1 cup of broth (or salted water) evenly over the spaghetti, pressing gently with a spoon to ensure the liquid reaches most of the pasta. It’s fine if a few ends poke above the surface; they will soften as they steam.

Dot the top with the remaining 1 tablespoon of butter. Cover the slow cooker and cook on HIGH for 45–75 minutes, checking and gently stirring after 30 minutes to separate the strands and prevent clumping.

Continue cooking, stirring once or twice more, until the spaghetti is tender but not mushy and coated in a glossy, buttery onion sauce. If the mixture seems too dry before the pasta is done, add a splash of hot water or broth, a few tablespoons at a time.

Once the spaghetti is cooked to your liking and the onions are deeply golden and silky, taste and adjust seasoning with a pinch more salt if needed (especially if you used low-sodium broth).

Turn off the slow cooker, let the pasta sit uncovered for 5 minutes to thicken slightly, then serve the onion spaghetti hot on warm plates, twirling strands so the caramelized onions cling to the pasta.

To stay true to the four-ingredient spirit, keep changes minimal and thoughtful. If you prefer, use all water seasoned with 1 teaspoon salt instead of broth; this is closer to what a Depression era cook might have done when stock wasn’t available. For a slightly richer flavor, brown the butter in a small pan before adding it to the slow cooker, which will give the sauce a nutty depth without adding more ingredients. You can also swap yellow onions for sweet onions if that’s what you have; they’ll cook down a bit faster and taste slightly sweeter. If you need to hold the dish for a bit before serving, switch the slow cooker to WARM and stir occasionally; add a splash of hot water if it thickens too much. For food safety, keep the slow cooker on HIGH or LOW only within its recommended time range and do not leave cooked pasta at room temperature for more than 2 hours. Refrigerate leftovers in a shallow container within 2 hours of cooking and reheat thoroughly until steaming hot before serving.