4large sweet onionspeeled, thinly sliced, and separated (Vidalia, if you can find them)
½cupunsalted butter
½cupsour cream
½cupgrated Mexican cheese blend
½cupgrated Parmesan cheese
1cupcrushed Ritz crackers (about 24 crackers)
Instructions
Add butter to a large skillet over medium heat. When the butter has melted, add the onions.
Reduce the heat to low and cook the onions uncovered for about 90 minutes. Stir about every twenty minutes.
When the onions are getting close to done, preheat the oven to 350 degrees F.
Place half of the onions in a small casserole dish, which has been greased or sprayed with non-stick cooking spray.
Add half the sour cream and spread out evenly.
Sprinkle half the Mexican grated cheese evenly over the top.
Top with half of the Parmesan cheese and half of the Ritz cracker crumbs.
Repeat the layers ending with a layer of Ritz cracker crumbs.
Bake uncovered for 25 or 30 minutes or until the mixture is bubbly and the topping is golden brown.
Video
Notes
Leftovers can be stored covered in the fridge for up to four days. I have never tried, but I don't think they would freeze well.
Reheat leftovers in the microwave for about 30 seconds.You can make this casserole up to eight hours ahead, but for the best results, do not bake it. Instead, cover and store it in the refrigerator. Then, about an hour before you want to serve it, take it out of the fridge to allow it to come to room temperature, and then bake as directed.I use a ten-inch cast-iron skillet for cooking the onions. It's ideal because it maintains the heat, and the onions cook perfectly without sticking or burning. A heavy bottom non-stick skillet will also work.The onions take a long time to caramelize properly. But, the good news, once you get them going, they don't need to be watched constantly. A quick stir every twenty minutes or so, and you are golden.Four onions may seem like a lot when you start, but they will shrink down to less than half of their size once cooked.I used a small round baking dish that was seven and one-half inches wide and two inches deep for this recipe, and it worked perfectly.The sour cream and cheese amounts may need to be adjusted slightly if your baking dish is larger or smaller than the one I used. If it's larger, you may need a bit more than the measurements shown.