Adapted slightly from Slow Cooker Comfort Food, this recipe serves 6.
4 slices bacon, chopped into 1-inch lengths
2 lbs stew beef, cut into 2-inch chunks
1/4 cup all-purpose flour
2 tsp olive oil
3 medium onions, thinly sliced
2 Tbsp packed brown sugar
4 large cloves garlic, chopped
1 tsp kosher salt
1 tsp fresh black pepper
2 bay leaves
1-1/2 Tbsp Dijon mustard
1 12-oz bottle beer or non-alcoholic beer (I use O'Doul's)
1 Tbsp cider vinegar
1/4 tsp cayenne pepper
4 cups chopped kale
In a large frying pan over low-medium heat, cook the bacon until it just begins to brown. With a slotted spoon, remove the bacon, leaving the fat in the pan. Transfer the bacon to a 5- or 6-quart slow cooker.
Place the flour in a mixing bowl. Dry the beef with a paper towel, and toss the chunks in the flour to coat; shake off the excess. Brown the beef on all sides, in batches if necessary so the pan isn't overcrowded. Transfer the browned beef to the slow cooker.
In the frying pan, add the oil and the onions, and sauté the onions until they start to brown. Add the sugar, garlic, salt and pepper, and cook, stirring, for 30 seconds, until the sugar dissolves. Stir in the bay leaves, mustard and beer. Bring to a boil, scraping with a rubber spatula to get up all of the brown bits in the pan. Pour the mixture into the slow cooker.
Cover the slow cooker, and cook on LOW for 8 hours, until the beef is quite tender.
In a small cup, stir together the cider vinegar and cayenne pepper. Add this to the beef, and stir.
Remove the bay leaves.
In two or three batches, add the kale to the beef. Submerge each batch with a spatula before adding the next batch. Turn the cooker to HIGH, and cook for 20-30 minutes, until the kale is cooked.
Serve hot, over pasta or egg noodles. Or, remove from the slow cooker, allow to cool to room temperature, and pack into containers. Refrigerate or freeze.