Preheat the oven to 375°F (190°C).

In a large bowl, mix together flour, sugar, baking soda, baking powder, salt, and softened butter. Stir in buttermilk and egg; mix until combined. Turn dough out onto a lightly floured surface and knead slightly. Form dough into a round and place on a prepared baking sheet. Use a sharp knife to cut an 'X' into the top of the loaf.

Bake until a toothpick inserted into the center of the loaf comes out clean, 30 to 40 minutes. Intermittently through baking brush the loaf with melted butter to get a nice golden brown top. Set a timer and check for doneness after 30 minutes. While baking, make the Shepherd’s Pie filling and potato topping.

In a pot of salted boiling water, boil the potatoes until a fork can easily slide in and out, about 8-10 minutes. While potatoes are cooking, make the filling.

Heat the oil in a non-stick pan. Sauté the garlic and onion until soft, about 3 - 4 minutes. Add the beef and brown while using a spatula to break it into smaller pieces. Stir in the flour and cook for 2 minutes. Season with salt and pepper. Stir in the broth, cream of corn, ground sage, and thyme. Cover with a lid and simmer until the broth concentrates in flavor and thickens. Taste and adjust the seasoning with salt.

Make potato topping: In a saucepan, melt the butter. Once the butter is melted, stir in the cream to warm.

Check the potatoes by inserting a fork into them; once the fork slides in and out with ease, take off of the heat and strain out all of the water. Mash the potatoes with a fork or potato ricer and return to the pot. Slowly add in the cream and butter mixture and whip until smooth. Season with salt and pepper to taste.

Make the Shepherd's Pie: Place the beef mixture into an appropriately sized oven safe dish; spoon the mashed potatoes on top or use a piping bag with a star tip (optional). Place under the broiler until golden brown.

Serve: Remove the shepherd’s pie from the oven and let sit for 2-3 minutes before portioning. Enjoy with soda bread and milk.