This is a very simple tart (especially if you use a bought pastry). The recipe is a bit loose as I made it up as I went along... So interpret as you will. The tang of the little purple guavas cuts through the richness of the ricotta; I don't think it needs a lot of sugar.

Pre-heat over to 180C

I amount of sweet pastry

Put pastry in 23cm (roughly) tart tin, chill for 30 mins, then blind bake for 10 minutes.
Remove the weights from the pasty case, and baste it thoroughly with some egg. Bake another 10 minutes.

(this seals the base and stops it going soggy)

400g ricotta
50g caster sugar
3 eggs (use a little of one for the
500 g little purple guavas, whole (frozen or fresh; an amount to cover the base of the tart fairly fully; use another fruit if you like)
optional - fine zest of a lemon or orange

whisk the ricotta, eggs and sugar (and zest)
pour over the fruit till fully covered
bake until set - 35 mins or so

best eaten at room temperature.