Place the peeled and cut potatoes into a large pot and cover with cold water. Add 1/2 teaspoon salt to the water.
Bring the pot to a boil over high heat, then reduce to medium and simmer until potatoes are tender, about 15-20 minutes.
While the potatoes cook, heat 1 tablespoon olive oil in a large skillet over medium heat.
Add the chopped onion to the skillet and sauté for 3-4 minutes until translucent.
Add the minced garlic and cook for an additional 1 minute until fragrant.
Add the ground beef to the skillet, breaking it apart with a spatula. Cook until browned and no longer pink, about 8-10 minutes.
Season the beef mixture with 1 teaspoon salt, 1/2 teaspoon black pepper, and 1/2 teaspoon paprika. Stir well and cook for another 2 minutes. Remove from heat and set aside.
Drain the cooked potatoes and return them to the pot.
Add 4 tablespoons unsalted butter and 1/2 cup whole milk to the potatoes.
Mash the potatoes with a potato masher or fork until smooth and creamy. Season with 1/4 teaspoon black pepper and adjust salt to taste.
Serve the seasoned ground beef alongside the creamy mashed potatoes.