Prick potatoes several times with a fork and place in a microwaveable baking dish. Drizzle with olive oil and season with salt. Microwave on high until fork-tender, about 6 minutes.

Meanwhile, heat a skillet over medium-high heat. Saute beef with onion, tomato, salt, pepper, and garlic powder until browned, 5 to 7 minutes. Stir in gravy and let simmer for 5 minutes.

Transfer potatoes onto individual serving plates and smash each with a fork. Cover potatoes with the beef mixture, then top with Cheddar cheese, bacon, and chives.