Chris' mom does these with shredded chicken, and really you can use any filler you want. I think the way we did the pork though added a ton of flavor and was a great variation. I think we'll try it next time with yet another filler!
Start with a pork shoulder. Ours was probably about 2 lbs, bone in. A little one, but there's only two of us. We then rubbed it all over in:
Pullman Pork Seasoning (a local spice shop blend, it's salty and garlicky and peppery)
Basically, you want to get some good spicy mexican flavors going.
Then put some oil in a pan, heat to smoking, and give the shoulder a nice crusty sear on all sides.
Next, place it in your crock pot surrounded with 1/2 an onion in large chunks.
With the remaining oil and brown bits in the pan, throw in the other half of the onion and some garlic. Cook them until they start to soften.
Here's where we're going to make the liquid to put in the crock pot!
Add 1 can of El Pato Tomato Sauce.
Unlike the pork seasoning, this can actually be purchased in Safeway/Dominicks/Tom Thumbs. You'll likely find it in the Mexican/Hispanic food section. This is a great spicy tomato sauce that kicks up the flavor in many Mexican foods.
Bring that to a simmer, stirring to get all the brown bits from searing the pork up off the bottom of the pan.
We also threw a little Chipotle Tabasco Sauce in, because we're addicted to the stuff, and hey, Chipotle is at least a Mexican flavor! (I told you we use it in everything.)
Finally, we added about 2 cups of chicken stock, and brought it all to a boil.
Once it reaches a boil, kill the heat and pour it in the crock pot. Now, this is a very important note. DO NOT pour the liquid directly on top of the pork. It will ruin the delicious seared crust on the outside. Either ladle the liquid in, or very carefully pour it around the pork. We did put a little of the El Pato sauce on the top of the pork, but that was just the El Pato sauce by itself, not the runny liquid mixture.
Now, put the top on, turn it on low, and wait patiently for at least 6 hours.
After 3 hours, you can start "basting" the pork, by just ladling some of the cooking liquid over it. Do this about every hour for the last few hours.
I'd like to note that although the picture above looks like a completely cooked pork shoulder, it's not done yet. It may be cooked through, but it's not done becoming delicious pulled pork yet. Leave it in. You'll know when it's ready because it will no longer look like a pork shoulder because it will have naturally begun to shred itself out of mouth-watering tenderness. Trust me on this one.
When it's actually ready to be taken out, it will look like this:
I promise you I in no way attempted to shred this at all. All I did was take off the top, and this is what the pork had done to itself. So I took a large slotted spoon and pulled it all out.
Next, start actually shredding it. You can remove the big bits of fat and the bone, but what is left should be mostly all meat. This is what I had left when I removed bad bits and kept the meat:
That is a LOT of meat, and very little throw-away.
Ok, now on to the fun part!
Quite unfortunately, I have no pictures of the fun part, because it involves very hot oil and quick, focused attention.
Get some flour tortillas (the medium or small size). Add some canola or peanut oil to a pan, 1/4 inch deep. Heat until it begins to smoke slightly. Now, put a tortilla in the oil until it puffs. This will take all of 3-4 seconds. With tongs, flip it over, until it puffs again, and remove and place on a plate with a paper towel on it. Repeat until you have lightly fried all of your tortillas, placing a paper towel between each one on the plate as you go.
Once you're done, bring them over to your meat.
Now place a row of meat toward one side of the tortilla. Since we're rolling these up, don't put the meat in the middle, otherwise you'll have a weird folded/rolled flauta.
Begin to roll it all up...
Do it for all the tortillas, or all the meat, whichever you run out of first!
Place them in a preheated 400 degree oven spread out on a baking sheet.
You will cook them until they brown on the outside, about 10-15 minutes.
While they are cooking, start to make a sauce.
Start with a basic enchilada sauce mix (powder and water). Then add some of the cooking liquid left over from the pork in the crock pot. Throw whatever else you want in there too, like more Chipotle Tabasco Sauce, salt, pepper, cumin, etc. I think we added all of those!
Bring it to a light boil. About the time you're done with this, the flautas should be done. Take them out of the oven, and they should look like this:
Now put some on a plate, cover them in the sauce, add whatever side you want (we added a little rice), and you're done!
I'd like to point out that if you make a ton of these, you can freeze them after rolling them up, but before cooking. We cooked too many, but we also froze some. If you bake them and have leftovers, they'll be good for another day or two if you heat them up in the toaster oven. If you freeze them unbaked, they will last a very long time and you can take them out and throw them in the oven/toaster oven when you need a quick meal. Delicious!