My love of cocktails is well documented. I might be nervous about Cooking Like a Grown Up, but point me at some cocktail ingredients and I'll mix you up something. My cosmopolitans are positively nuclear in their glow.

In The Girl in the Fireplace, the Doctor claims to have invented the Banana Daiquiri two centuries early. Which is possible - certainly more possible than me repeatedly typing banana daiquiri without falling into typing the Pratchettian banananananana daiquiri - since both rum and, iirc, bananas were around in the 1740s. Although admittedly the only rum then available was dark (and therefore considered suitable only for the working classes) and bananas were very rare in Europe...sorry, getting distracted by historical details, again.

In the interests of Science therefore (that science being mixology), I had a go tonight. I tried to make it with:
2 x shots white rum
1 x small banana, sliced
juice of 1/2 lime
juice of 1/2 orange*
dash of apple juice*
ice

The orange is to replace the triple sec (based on the fact that some recipes replace triple sec with cointreau which is orange flavoured) and the apple juice is to sweeten as I am also out of bar sugar.

Put the ingredients into a jug. Smoosh with hand-blender till smooth. Pour into cocktail glass.
Drink.

After the all important taste test, I think it does need either the triple sec, cointreau or a third shot of white rum.

I am starting to consider creating a cocktail to match each episode of the new series. Although a banana daiquiri is mentioned in GitF, I don't think it is quite the right drink to go with it. It needs some bitters to match the romance, perhaps more lime...? I'm not a fan of heavy fruit cocktails, anyway, prefering clear ones such as the Hemingway Daiquiri.