1 Scrub The Potatoes; Do Not Peel. Place The Potatoes In A Large Pan, Cover With Water And Boil, Covered, Until Tender When Pierced, About 20 Minutes. Drain And Place In A Serving Container. Keep Warm. 2 Melt Butter In A Frying Pan Over Medium Heat. Add Chopped Onion And Green Onions And Cook Until Limp. Add The Tomatoes And Cook, Stirring Often, For 5 Minutes. Stir In The Cream, Cilantro, Oregano, Cumin, And Salt And Pepper To Taste. While Stirring, Slowly Add The Cheese And Cook Until The Cheese Is Melted. 3 If Potatoes Are Not Small, Cut Them In Halves Or Quarters. Spoon The Sauce Over The Potatoes.