Cut chicken (or your chosen protein) into bite-sized cubes about 1.5 inches. Season generously with 1 tablespoon Cajun seasoning and let rest for 15 minutes to allow flavors to penetrate the meat. Pro tip: Room-temperature ingredients mix more smoothly with the cream base, so take your cream and milk out of the fridge 30 minutes before starting.

Dice your onion and mince fresh garlic. Chop bell peppers into bite-sized pieces. Having everything prepped (mise en place) makes the slow cooking process incredibly smooth. Pro tip: Prep your vegetables the night before and store in airtight containers for true hands-off morning cooking.

Heat 2 tablespoons butter in a large skillet over medium-high heat. Once foaming, add seasoned protein (chicken, shrimp, or sausage) and sear for 3-4 minutes per side until golden brown. Don't worry about cooking through—it will finish in the slow cooker. Pro tip: Searing creates a flavorful crust that adds depth. For shrimp, just 2 minutes per side prevents overcooking since it cooks quickly later.

In the same skillet, add remaining 2 tablespoons butter. Sauté diced onion for 3 minutes until softened and fragrant. Add minced garlic and cook 1 minute more until you can smell that wonderful garlic aroma. Pro tip: Don't let garlic brown or it becomes bitter. The moment it's fragrant, move to the next step.

Pour room-temperature heavy cream and whole milk into your slow cooker insert. Add the seared protein, sautéed onions and garlic, and diced bell peppers. Stir well to combine. Pro tip: Cold cream can slow down the cooking process and create lumps, so always use room-temperature dairy for slow cooker cooking.

In a small bowl, whisk together Cajun seasoning, paprika, cayenne pepper, salt, and black pepper. Slowly add this spice mixture to the slow cooker while stirring constantly. This prevents spice clumping. Pro tip: Taste the sauce before adding pasta and adjust seasonings. Cajun blends vary by brand, so you might need more or less depending on what you use.

Add chicken broth and stir thoroughly. Cover and cook on LOW for 4 hours, stirring occasionally (about every 45 minutes) to prevent the bottom from sticking. Pro tip: Don't skip the stirring—it ensures even cooking and prevents scorching, which can happen with cream-based sauces in slow cookers.

While the slow cooker does its magic, cook your pasta according to package directions in a separate pot of heavily salted boiling water. Cook until just al dente (a minute or two before fully tender), then drain well. Pro tip: Cooking pasta separately prevents it from becoming mushy. The pasta will cook slightly more in the slow cooker as everything melds together.

When the slow cooker sauce has cooked for 4 hours, add the freshly grated Parmesan cheese, stirring constantly until completely melted and integrated. The sauce should be silky and creamy. Pro tip: Add cheese gradually while stirring to prevent clumping. If you add it all at once, you might end up with grainy Alfredo instead of smooth and creamy.

Add your drained pasta to the slow cooker and fold gently to coat everything evenly. Cook on LOW for 15-20 minutes more, stirring occasionally, until pasta is tender and sauce clings beautifully to each piece. Pro tip: Taste for seasoning and adjust salt or spices as needed. Remember that Parmesan adds saltiness, so be careful not to oversalt.

Transfer to serving bowls and garnish generously with fresh Italian parsley, sliced green onions, and Parmesan shavings. A pinch of red pepper flakes adds visual pop and a hint of heat. Pro tip: Serve immediately while everything is creamy and warm. This slow cooker Cajun Alfredo is best enjoyed right after finishing, though it reheats beautifully.