This is probably one of the easiest meals I ever make!
Thinly slice one onion and place in the bottom of crockpot.
Brown one roast in a cast iron or some other pan that is NOT Teflon coated. You need a good sear on the roast and non stick pans will not give you that sear. When the roast is good a brown on all sides place roast in crockpot on top of onions.
Deglaze the pan you browned the roast in with 1/4 to 1/2 cup water, use only what is needed to get any brown bits off the bottom of the pan. This makes a great juice and pour it on top of the roast.
Finely chop or use garlic press and crush fresh garlic to taste. I like lots of garlic so I will use 3-4 cloves depending on their size. Place on top of roast.
Sprinkle with salt and pepper, and add about 1 1/2 tsp of better than bullion beef.
Cover, cook on low for 6-8 hours, can cook on high if you need to for 4 hours but the roast may not come out falling apart tender.
When the roast is done, the inside of the crockpot should have a very thin layer of meat brownings. Using very hot water, and wire whisk, you can pour the hot water over this and scape it down into the juices in the bottom of the pan. Generally, when I make this I end up with about 2 cups of homemade Aujus, that tastes better than a package from the store.
Serve with bread or rolls.
Place small bowls at the each plate to pour the juice into for dipping the sandwiches.
Note, this is one of my favorite low carb recipes, while my family enjoys the bread, I eat the roast with what ever vegetables I fix.