Rotel makes a good Queso in a hurry, when you need it. Recipes are also on the Velveeta box.
This is the Homemade one I grew-up eating, and still use today. (I add lots of Jalapenos, as we like it hot.)
Chile Con Queso
1 Box Velveeta Cheese (large one) cut into chunks
1 medium onion (yellow or white) chopped
3 to 4 Jalapenos chopped (the canned ones or fresh)
1 14.5oz canned chopped tomatos (no need to drain)
2 large cloves garlic minced
3 tablespoons butter
1/4 cup Milk
In a large sauce pot, melt butter...add the onions and cook until soft...add garlic...saute just until you smell garlic...add the jalapenos...add can of tomatos... let simmer for a couple minutes...add Velveeta chunks and milk...(have heat on low at this point) stir occasionally until cheese has melted completely (you may want to add more milk, depending on thickness)
The Jalapenos may be substituted with 3 cans of the 4oz Green Chiles if you'd like.....
This can be made a couple days in advance and keep in the fridge!!!! (you will want to re-heat on low, and add alil milk to the bottom of the pot before you put Queso in)
I serve mine in the Crockpot (on lowest setting) to keep nice and warm for the tortilla chips!