Food safety tips: Always brown the ground beef thoroughly before adding it to the slow cooker; it should reach an internal temperature of 160°F and show no pink. Drain off excess grease so the casserole doesn’t become oily. Keep the slow cooker on LOW or HIGH as directed; do not use the WARM setting to cook from raw, as it won’t bring the food into a safe temperature range quickly enough.
If you’re prepping ahead, brown the beef and cool it completely in the refrigerator before assembling the casserole, and keep all components chilled until you’re ready to start the slow cooker. Leftovers should be cooled, then refrigerated within 2 hours and eaten within 3–4 days, or frozen for up to 2–3 months.
