May one buy non-Kosher food for a gentile, such as an employee?
Regular gentile, non-employee: It is forbidden to purchase non-Kosher food for a gentile due to the business prohibition. This applies even if one is giving the gentile the food as a present and certainly if he is selling it to him for a profit.
Employee: It is debated amongst the Poskim if providing his employees with non-Kosher food transgresses the business prohibition and practically one may be lenient in a time of need. However, initially one is to either provide them with a Kosher meal.
Foods forbidden in benefit: It is forbidden to purchase foods forbidden in benefit [i.e. Yayin Nesech, Basar Bechalav] for the sake of giving it to any person or even animal. [Thus, one may not purchase a cheeseburger, or non-Kosher wine for the sake of giving it to a gentile.]
Paying for the food after it is eaten: If the meal will only be paid for by the Jew after it is already eaten or acquired by the gentile [i.e. paying a bill at a restaurant after the meal] then it is permitted to do so. This applies even if the gentile orders non-Kosher food that is prohibited in benefit and one is obligated to provide the employee with his meals.
 Rama 117:1; Shach 117:3; Beis Yosef 117; Hagahos Maimanis; Peri Chadash 117:3; Kaf Hachaim 117:52
Other opinions: Some Poskim rule one may purchase and feed non-Kosher food to a gentile. [Kneses Hagedola 119:9, brought and negated in Kaf Hachaim ibid]
 The reason: As buying non-Kosher food for a non-employee is considered as if one is giving him a present, and a present is viewed as business, as the present is given with intent to receive something in exchange. [Beis Yosef ibid; Poskim ibid]
 Some Poskim rule it is forbidden to purchase non-Kosher food for the sake of feeding one’s employees due to the business prohibition. [Rama 117:1; Taz 117:2; Peri Toar 117:3; Rash and Ovadia Bartenura Dmaiy 3; Erech Hashulchan 117:3; Peri Hasadeh 3:193; Zivcheiy Tzedek 117:7] Other Poskim, however, rule that it is permitted to do so and that so is the custom. [Shach 117:3; Peri Chadash 117:3; Aruch Hashulchan 117:19; Makom Shmuel 77; Chochmas Adam 69:1] See Kaf Hachaim 117:12 and 52; Levush 117:1; Pischeiy Teshuvah 117:4; Maharam Brisk 2:56; Pnei Meivin Y.D. 101; Beis David 117:13; Neta Shurak Y.D. 41; Daiy Hasheiv 5; Darkei Teshuvah 117:28; Chelkas Binyamon 117:12; Teshuvos Vehanhagos 2:394 and 393
 The reason: As providing one’s workers with food is not viewed as performing business with the food. [Shach ibid; Peri Chadash ibid]
 See Maharam Shick 136 that a G-d fearing Jew is to suspect for the stringent opinion which prohibits providing the emplopyees with non-Kosher food, however, one need not protest against those who are lenient;
 See Admur 450:23; Taz 94:4; Toras Chatas 85:3; Shaareiy Dura 5; Issur Viheter 21:12; Tashbeitz 3:293; Kneses Hagedola 87:10; Peri Chadash 94:10; Hakdama of Yad Efrayim; Shulchan Gavoa 87:3; Erech Hashulchan 87:7; O.C. 448:7; Chochmas Adam 40:2; M”B 448:28 and Shaar Hatziyon 448:75 that so is simple implication; Kaf Hachaim 87:4; O.C. 448:108; So rule regarding Chametz that it is forbidden to be given to even wild animals that are not owned: Admur 443:3; Michaber 448:6; Taz 443:3; M”A 448:9; Levush 448; See Mateh Yehuda 448; Mor Uketzia 448
 See Admur 450:23 regarding Chametz from where it is clear that having the gentile take the food on credit circumvents both the business and benefit prohibitions from being transgressed by the employer.; 2nd opinion in Michaber 450:6; Mordechai Remez 549; M”A 450:9 that so is main opinion; Hagahos Mahrshal on Tur 450; Peri Chadash 450:6
Other opinions: Some Poskim rule it is forbidden to have the gentile buy for himself Chametz on the basis that one will pay him, or the store owner, back. [1st opinion in Michaber ibid]