The Shulhan Aruch (siman 242) discusses the importance of the Misva of Oneg Shabbat (Pleasure on Shabbat). This Misva is already mentioned by the Navi Yeshaya, "And you shall call the Shabbat enjoyable."
Oneg Shabbat is fulfilled by enjoying fine foods and beverages. The Rambam cites the custom to partake of "basar shamen"- choice cuts of fat meats. He does not mean fatty foods necessarily; he means foods that are tasty to the person. In the times of the Gemara, people would enjoy sizable fish, garlic or beets on Shabbat.
Accordingly, Rabenu HaAri Hakadosh says that on Shabbat, not only do we perform a tikun with our special tefilot, but also with our special Shabbat meals. Therefore, the Halacha states that even if a person is on a tight budget, he should set aside money to purchase some type of Shabbat delicacy.
The Ben Ish Hai (Rav Yosef Haim of Baghdad, 1833-1909 , Rav Pa'alim, Vol. 3, Ohr Hahaim 22 ) asks whether the misva of Oneg Shabbat is mandated D’oraita (by Torah Law) or D’Rabanan (Rabbinically Ordained). He brings a very interesting proof from a Targum Yonatan ben Uziel in Parshat Ki Tisa on the pasuk "And the Children of Israel shall keep the Shabbat, to make the Shabbat". The Targum Yonatan asks, what does the pasuk mean "to make the Shabbat"? On the contrary, Shabbat is kept by refraining from action, not making action.
He explains that the Torah is requiring us to make "delightful treats," i.e. delicious food and drink in honor of Shabbat. From here, the Ben Ish Hai extrapolates that Oneg Shabbat is a Misva D'oraita.
He also brings the opinion of the Rashba ( Teshuvot HaRashba 1:127|) that it is a misva from the Torah. While, some Achronim do hold that it is D’Rabanan, the Ben Ish Hai concludes that it is, in fact, D’oraita. Therefore, upon eating the Shabbat meals, one should have kavana to fulfill the Torah Misva to have Oneg Shabbat.
SUMMARY: It is a Torah Misva to enjoy delicious food and Drink on Shabbat according to a person’s taste.
