Place a non-stick skillet on medium-high heat.

When the skillet is warm, add the oil and warm through until the oil is shimmering.

Meanwhile, line a plate with paper towels and set near the stove.

Brown the beef in batches, using a heat-proof spatula to break up big clumps. Once the meat is browned, use a slotted spoon to transfer beef to the prepared plate.

Once the meat has been browned, lower your heat to medium and add the onion to the pan. Cook for 3-5 minutes, so the onion can begin to soften. Then add the garlic and cook for another 1-2 minutes.

Add the drained beef, onions and garlic to your slow cooker, and turn off your stove.

Add the rest of the ingredients (except the toppings) to your slow cooker. Use a wooden spoon to stir everything together, then put the lid on. Set your slow cooker on low for 7-8 hours or high for 4-5 hours.

Be sure to adjust the seasoning before eating, if needed. Serve with desired toppings.