Slow cooker, put 2kg brisket and ~120ml water in, low setting, 8 hours. Put brisket on rack, coat with a mix of tomato sauce, BBQ sauce, and mustard. Into oven at 200°C for about 20 minutes. Take it out, wrap in foil, cool until near freezing, then slice thin.
This is cheaper for 4 days of lunches than one day of takeaway for me. No nursing the food, just set a reminder and forget.