Preheat oven to 350°F.

Slice russet and sweet potatoes into 1-inch chunks. Add to a saucepan and fill with water until covered. Simmer over medium-high heat for roughly 20 minutes, or until potatoes are soft enough for mashing.

Meanwhile, for the filling, slice celery stalks lengthwise in half, then chop into 1/2-inch pieces.

Chiffonade pineapple sage and basil leaves into thin ribbons. NOTE: If you can't find pineapple sage, use regular sage leaves and add some orange zest. It should be close.

Add a tablespoon of butter to a medium skillet and melt over medium-low heat. Add celery, pineapple sage, basil, 1/4 teaspoon of salt, and a dash of black pepper. Saute on medium-low for 10 minutes, or until celery had just lost its crispness.

Set aside cooked celery in a medium-sized bowl. To the same skillet celery was cooked in, add ground beef, 1/4 teaspoon of salt, a dash of black pepper, and the crushed red pepper. Increase heat to medium and cook 7 minutes or until cooked through.

While the beef is cooking, strain the cooked potatoes and return to saucepan. With a mixer or by hand, mash the potatoes with the butter, sour cream, salt, pepper, tarragon, and smoked paprika.

Transfer cooked beef to bowl with celery and mix together. Pour the mixture into the bottom of a small baking dish. Then, spread the mashed potatoes on top to cover completely.

Bake at 350 for 20 minutes.