I don't own a crock pot, but I assume this would work in one. My secret here is patience and a heavy pan, like a cast iron stock pot. I use my Mamaw's old heavy aluminum roasting pan, being careful never to use an acidic food like tomato in it.
Another thing is, I don't use onion soup mix. I guess one could, but onion soup mix is mostly dehydrated onion and dehydrated soy sauce anyway.
One roast (beef or pork). I buy the cheapest cut because this recipe will tenderize just about any cut of meat. I've even used it with venison with rave reviews. With this recipe, it isn't the meat or the cut of meat that makes the meal-its the add-ons and method. You can also put a roast straight from your freezer in there without thawing first.
1/2 cup soy sauce
2-3 tablespoons dehydrated onion
A teaspoon or so of Mrs. Dash (or a heavy sprinkling of black pepper)
Fresh or frozen stew veggies (canned ones fall apart and taste too bland). If FRESH, put in pan with roast at least an hour before suppertime. If frozen, 30 minutes.
Put the onion, seasoning, and soy sauce in the pan. Add the meat, and fill with water just to where it covers the roast. Cook at 275-300 degree oven for 6-8 hours. Add veggies as per instructions above.
I serve this with rice and yeast rolls. The juice makes a wonderful gravy, and an even better beef stew the next day.