Support H.R. 770. Oh, and go pee in the ocean, too.

H.R.770

Title: To prohibit the use of funds to carry out any covert action for the purpose of causing regime change in Iran or to carry out any military action against Iran in the absence of an imminent threat, in accordance with international law and constitutional and statutory requirements for congressional authorization.

LINK

This initiative has been around almost all year and probably has little chance of passing. Even if it does, our newly-ensconced unitary executive branch is apt to find a way around it.
The symbolism, however, is important, especially in light of all this talk about "democracy."