For herb lovers, stir 1 to 2 teaspoons of dried Italian seasoning or a tablespoon of finely chopped fresh parsley or rosemary into the garlic butter before spreading it on the steak (this technically adds an ingredient, but it’s an easy upgrade if you’re not strict about the 4-ingredient rule). To add gentle heat, mix a pinch of crushed red pepper flakes into the butter. If you’d like a slightly more robust crust, you can sear the steak pieces quickly in a hot skillet with a touch of oil before placing them on the foil; this step is optional but adds flavor and color. For smaller households, halve the recipe and use a smaller slow cooker, keeping the same cook time but checking a bit earlier. These packets also adapt well to different cuts: use chuck steak or blade steak for a more pot-roast-like tenderness, or ribeye for extra richness (just watch the time, as fattier cuts can cook a bit faster). Leftovers reheat gently in the foil in a low oven or can be sliced thin and served over salads or tucked into sandwiches with any remaining garlic butter.