Heat the olive oil in a large skillet over medium-high heat and sear the cubed beef chuck until deeply browned on all sides.
Add the diced onion, carrots, and celery to the skillet, sautéing for about 5 minutes until the vegetables begin to soften and caramelize.
Stir in the tomato paste, sea salt, black pepper, and fresh thyme, ensuring the beef and vegetables are evenly coated.
Pour in the golden ale to deglaze the pan, scraping the bottom to release the flavorful bits, then add the beef bone broth.
Reduce the heat to low, cover the skillet, and simmer for 20-25 minutes until the liquid has reduced into a thick, savory gravy.
Transfer the beef mixture into a small oven-safe ramekin or baking dish, spread the mashed Yukon gold potatoes over the top, and broil for 3-5 minutes until the surface is golden brown.