The Se’uda Mafseket – the final meal that one eats before the onset of the fast of Tisha B’Ab – may consist of only one cooked food. There are no restrictions on raw foods, but only one cooked food item may be included in this meal.
However, two foods that are normally cooked together in a single dish are considered as one food for the purposes of this Halacha. Thus, for example, if a person cooks lentils and rice together, this dish may be served at the Se’uda Mafseket, as the rice and lentils are considered a single food. Even though the pot contains both rice and lentils, we regard this dish as a single cooked food because they were cooked together, and it is common to do so. Another example would be macaroni and cheese. Since it is common to cook noodles and cheese together, this would be considered a single cooked food. It should be noted, however, that if one cooks the noodles and cheese separately, they are considered separate foods and they may not both be eaten at the Se’uda Mafseket.
Pizza, strictly speaking, may be eaten, even though it contains several different foods, since they are all baked together. Nevertheless, Hacham Ovadia Yosef writes that one should preferably not eat pizza at the Se’uda Mafseket, as it is generally associated with fun gatherings and it is thus inappropriate for the mood that should prevail during the Se’uda Mafseket.
Milk is not considered "cooked" with respect to the Se’uda Mafseket even though it has undergone pasteurization. Since the process does not alter the taste in any way, and is done merely to kill bacteria, the milk is considered a raw food as far as the laws of Se’uda Mafseket are concerned. This is the ruling of Hacham Ovadia Yosef as well as Hacham Bension Abba Shaul (Israel, 1923-1998).
Summary: One may not eat more than one cooked food during the final meal before Tisha B’Ab, though two foods that are normally cooked together – like macaroni and cheese – are considered a single food with respect to this Halacha, unless they are cooked separately.
