Melt 1/2 stick (1/4 cup) butter in heavy skillet. (not non-stick)
Chop 1/2 of a sweet onion (or more) and saute in the butter over medium heat.
Take about 1 pound skirt steak, or other long-grained beef with minimal fat. Cube small. When onions are wilted and beginning to brown, add steak and increase heat to medium-high. Brown all over, stirring as necessary, until the liquids are gone and the sugars start to caramelize and stick.
Meanwhile, peel and chop small: 1 parsnip, 2 carrots, 2 medium red potatoes, 2 stalks celery and 1 smallish shallot. Put in slow-cooker on high heat with enough water to let vegs swim freely.
When the beef and onions are well-browned, add them to the slow cooker. Return skillet to heat and add about 1 cup water to deglaze, scraping up all the brown bits. Add to crockpot. Add about 1/2 cup red wine, or cooking sherry and a dash of balsamic vinegar.
Season with 2-3 beef bouillon cubes (take care not to make it too salty), salt and pepper (I like Lowry’s seasoned salt and seasoned pepper), 1/2 tsp rosemary, 1/2 tsp thyme, and a pinch cayenne. If you don’t use the Lowry’s, add also a dash of sugar and 1 teaspoon of paprika.
Melt the other 1/2 stick (1/4 cup) butter in the skillet and add 1/4 cup flour. Cook and stir over med-high heat until it turns a nutty brown color. Add to pot.
Leave in the slow cooker on High for about 3.5-4 hours.