The treasurer will report the event in J1 of the SEEC Form 30 (or L1 of the SEEC Form 20 for municipal candidates), answering yes to whether the event was held at a personal residence. While the section categorizes them as "fundraising events," the house party should be listed here, even though it was not a fundraiser.
Then, in J3 of the SEEC Form 30 (or L4 of the SEEC Form 20 in the case of municipal candidates), the treasurer will list all of the host's expenses for the party, listing the corresponding event number assigned in J1 (or L1 in the case of a municipal candidate). The treasurer will then itemize Wendy's donations in the same section, again listing the corresponding event number. If the candidate is nonparticipating or running for municipal office, then Stella's steaks would be reported as an in-kind contribution in Section K of the SEEC Form 30 (or Section M of the SEEC Form 20), listing the corresponding event number as well.