Instead of treating your date to a superbly cooked meal at your favorite restaurant, why not impress her with a frugal meal for two. With the money you save you could make her (or his) night complete by paying for their bus fare home.
Start with a nice cheap soup. Its your big opportunity to use up some of the items at the back of the fridge (but don't forget to cut off the mouldy bits). Add a touch of curry powder to this to disguise the stale taste.
A good nutritional main meal could be baked beans on toast. Beans are a good source of protein and fibre and have very few side effects.
Then finish off the evening with cheese and biscuits. This will save money on the cooking. For a cheaper recipe exclude the cheese.
I hope these ideas have been of some use to you.
Happy courting.