Make Chilli. Cheap and Yummy. However, it an be hazardous, particularly if you are a little drunk. And if your flatmate has "researched" how to properly dice an onion. How to properly and cunningly get your innocent flatmate and alleged "best friend" to dice her OWN FINGER more like. Grr, grr.
But yes! Chilli! What you need to do is go to Edecca's meat counter (cheaper by some cents than getting it from the fridge and it doesn't come in those sad little boxes) and get some mince (1.73€ for 500g of Rindfleish mince which will do you a sizeable chilli AND A bolognaise) and then some beans (remember- Lidl is best for tins!) and oinons (you can get loads of Ja! Spiesen oinions in Reve for like 70c. Oh my God, could my knowledge of supermarkets be anymore in-depth/tragic?) and put them all in a pot with spices etc etc (my knowledge lies in supermarket deals, I cannot profess to be a chilli expert. Look it up elsewhere). It is best also if you can find a good quality-and-chilli-suitable pot "zu verschenken" in your friend's appartment building an nab it before she can, as I did yesterday- result! Making chilli is immensely satisfying and makes you feel homely and motherly. It is also entertaining to cook tipsy. Not least for onlookers. Also, CHEAP but with a level of danger (how spicy will you go? will my finger stop bleeding anytime soon?) that you might well be expected to pay for in other contexts.