Lightly grease the inside of your slow cooker with a little butter or nonstick spray to help keep the pasta from sticking.
Lay the dry linguine in the slow cooker, breaking the noodles in half if needed so they fit in an even layer. The dry noodles should be visible on the bottom, just like in the photo of shrimp over uncooked pasta.
Pour the chicken broth evenly over the dry linguine, making sure most of the noodles are moistened. Gently press any very dry pieces down into the liquid with a spoon.
Scatter the minced garlic over the pasta, then add the butter pieces on top. Sprinkle with salt, black pepper, and crushed red pepper flakes if using.
Place the raw shrimp in an even layer on top of the butter and pasta. It’s fine if some shrimp overlap; just try to spread them out so they cook evenly.
Cover and cook on HIGH for 1 hour. After 1 hour, open the lid and gently stir the pasta, shrimp, and sauce together, breaking up any noodles that are clumping. The shrimp should be pink and opaque and the pasta close to al dente.
Sprinkle the grated Parmesan cheese over the mixture and stir again until the cheese melts into the buttery broth and coats the pasta and shrimp. If the pasta seems too firm, cover and cook on HIGH for another 10–15 minutes, checking once or twice and stirring gently.
Taste and adjust seasoning with a little more salt or pepper if needed. If the sauce feels too thick, you can splash in a bit of hot water or extra broth and stir until creamy.
Turn the slow cooker to WARM. Let the pasta sit for 5–10 minutes so the sauce thickens slightly and clings to the linguine.
Just before serving, sprinkle with chopped fresh parsley if you like, then twirl the linguine onto plates, topping each portion with plenty of shrimp and extra sauce from the bottom of the slow cooker.
Variations & Tips
For picky eaters, you can cut the red pepper flakes entirely and go a little lighter on the garlic; the butter and Parmesan still give plenty of flavor. If your family loves extra saucy pasta, add up to 1/2 cup more chicken broth at the beginning and an extra 1/4 cup Parmesan at the end. To sneak in veggies, stir in a couple of handfuls of baby spinach or frozen peas during the last 10 minutes of cooking; they’ll wilt and blend right into the pasta. You can swap the chicken broth for vegetable broth if you prefer, or use salted butter and reduce the added salt. If you only have spaghetti or fettuccine on hand, those will work in place of linguine; just keep an eye on the pasta and add a splash more broth if it looks dry. For a slightly richer, restaurant-style version, stir in 1/4 cup heavy cream or half-and-half along with the Parmesan. Leftovers reheat best with a spoonful of water or broth added before warming so the sauce loosens back up. And if someone in the house isn’t a seafood fan, you can cook a little chicken on the side and toss their portion of pasta with that instead of shrimp, using the same buttery garlic sauce from the slow cooker.
