The 
uke
only appears in one scene, as the judge of Antonio's
trial, although we hear of him earlier in the play from Solanio
and Salerio (they tell of him going with Shylock
to look for Lorenzo and Jessica).
Here's the thing: he's not really impartial. Just like everyone else, he
thinks Shylock's bond is cruel. Consider his opening speech:
| "Shylock, the world thinks, and I think so too, / that thou but leadest this fashion of thy malice / to the last hour of act, and then 'tis thought / thou'lt show thy mercy and remorse more strange / than is thy strange apparent cruelty; / and where thou now exacts the penalty, / which is a pound of this poor merchant's flesh, / thou wilt not only lose the forfeiture, / but, touched with human gentleness and love, / forgive a moiety of the principal, / glancing an eye of pity on his losses / that have of late so huddled on his back..." (IV.i.16-28). |
Some judge! The Duke is going into the trial thinking that Shylock's bond is not valid, and that Shylock himself will probably relent. So is it any surprise that Portia wins the trial for Antonio? Sure, she makes some great arguments, but some would argue that if the trial were real, her arguments would not be enough to win. Of course, in real life, no bargain like this would ever hold, but hypothetically, even though Shylock's bond is cruel, Antonio did agree to it. And he didn't uphold it. This could turn into a long debate. Discuss it amongst yourselves while I have a snack...
So what did you come up with? You may want to visit Shylock's Links to look at more on the trial.
Otherwise, your options are: 
or The
Duke's Links.
Portia / Shylock / Bassanio / Antonio / Gratiano & Nerissa / Lorenzo & Jessica / Salerio & Solanio / The Gobbos / The Princes / The Servants