Preheat the oven to 350 degrees F (175 degrees C). Line a baking sheet with aluminum foil.

Prick potatoes several times with a fork. Place onto the prepared baking sheet; drizzle with olive oil.

Bake in the preheated oven until potatoes are easily pierced with a fork, 60 to 75 minutes.

While the potatoes are baking, heat olive oil in a large skillet over medium-high heat. Add mushrooms, bell pepper, and onion; saute until onion is translucent, about 5 minutes. Add garlic and cook for 2 to 3 minutes more. Add ground beef and sausage; cook, breaking up into small pieces, until browned and crumbly, 5 to 7 minutes. Stir in summer savory and steak seasoning.

Push meat mixture to the sides of the skillet; melt butter in the center. Add flour to the melted butter; whisk to combine and cook for 1 minute. Whisk in beef stock, Worcestershire sauce, soy sauce, and mustard. Season with salt and pepper; simmer until thickened, 3 to 5 minutes.

Remove potatoes from the oven. Allow to cool slightly, about 10 minutes. Slice each potato in half lengthwise. Scoop the flesh into a large bowl, saving the potato shells. Add 3/4 cup Gouda cheese, green onions, sour cream, paprika, salt, and pepper to the potato flesh; mash well to combine. Allow to sit for 5 minutes so flavors can meld.

Place the potato shells on the aluminum-foil lined baking sheet. Fill the shells with the meat mixture, then top with the potato mixture. Sprinkle with remaining Gouda.

Bake until cheese is melted and potato mixture is golden brown, 10 to 15 minutes.