Chara has managed to locate tea; took them a while because the fact it's in a tin as loose leaf and not in teabags threw them off. But it says Earl Grey on the front, and that's a kind of tea, is it not?

They place it on the bench next to the sink, sliding it towards other-Frisk with a push of an index finger. When the other Frisk glances over their shoulder they take the opportunity to sign before their attention has to return to what they're doing.

[I see. Is the Castle tea like monster tea, then?]

That is, having some healing magic in it, no matter how small.