1 tablespoon olive oil
2 pounds Yukon Gold potatoes, peeled and quartered
1 tablespoon salt
2-1/2 cups milk, divided
2-1/2 cups cheddar cheese, shredded, divided
2 tablespoons butter
2 tablespoons all-purpose flour
4 slices of bacon, chopped
2 pounds lean ground beef
1 onion, small dice
2 cloves garlic, minced
3/4 cup ketchup
1/4 cup mustard
1 teaspoon Worcestershire sauce
Preheat the oven to 375 degrees F and coat a 2-quart circular baking dish with the olive oil.
Place the potatoes in a large pot and fill with enough water to cover them by two inches.
Add salt to the potato water and set over high heat.
Bring the potatoes to a boil, and lower heat and simmer for about 20 to 30 minutes, until they can be pierced with a fork.
Drain the potatoes before adding them back to the pot.
Add 1/2 cup of milk and 1/2 cup of cheddar cheese. Mash with a potato masher and set aside.
While the potatoes are cooking, make the cheese sauce. Melt the butter in a medium-sized pot over medium heat.
Add the flour and whisk to combine. Cook for two minutes to remove the raw flour flavor.
Slowly pour in 2 cups of milk, whisking as you do to prevent lumps from forming.
Turn the heat under the sauce to low. Simmer for 10 minutes to allow the cheese sauce to thicken slightly.
Remove the sauce from the heat, and slowly add 2 cups of cheddar cheese, stirring after each addition. Set aside.
Place the bacon in a cold frying pan. Set over medium heat and cook until brown and crispy.
Remove the bacon from the frying pan and set on a plate lined with paper towels to drain.
To the bacon fat, add the ground beef, breaking it up as you do.
Cook the ground beef, stirring and turning regularly, until very little pink is left. This should take about 8 minutes.
Add the onion and garlic to the ground beef. Stir, and cook for another 3 minutes.
Place the ground beef mixture, cheese sauce, bacon, ketchup, mustard and Worcestershire sauce into a large bowl. Mix well.
Pour the beef mixture into the bottom of the prepared baking dish.
Spoon mashed potatoes on top of the ground beef mixture.
Place the glass baking dish onto a baking sheet to catch any drips.
Place the baking sheet into the oven and bake for 20 minutes, or until the entire dish is hot and bubbling throughout.