Season the beef cubes on all sides with salt and pepper. In a large, ovensafe pot or Dutch oven over medium-high heat, add the butter. Add the ground beef, season with salt and pepper and cook until browned, 5 to 8 minutes. Remove to a plate. Working in batches, sear the beef cubes and jalapeno halves on all sides, about 10 minutes. Remove to a bowl, leaving the fat in the pot. Toss the seared beef cubes and jalapeno with the flour.
Preheat the oven to 250 degrees F. Add the onions, paprika and sage to the pot and cook, stirring, until the onions are tender, 5 to 7 minutes. Add the garlic, ground and cubed beef and jalapenos to the pot. Add the beef stock and 1 cup of the coffee. Season with a pinch of salt. Cover and cook in the oven until the beef is tender, about 4 hours.
At the 4-hour mark, add the potatoes, carrots and remaining 1/2 cup coffee. Cover and continue to cook until the potatoes and carrots are tender, about 1 hour. Skim off any fat from the top, then spoon the stew over the rice. Sprinkle with parsley before serving.