Begin by peeling and chopping your potatoes into uniform chunks. This will ensure they cook evenly. Rinse them under cold water to remove excess starch, which contributes to a creamier texture.

Place the chopped potatoes in a large pot and cover them with cold water. Salt the water generously. Bring it to a boil over high heat. Reduce to a simmer once boiling, and let them cook until fork-tender, about 15-20 minutes.

While the potatoes are boiling, melt ½ cup of unsalted butter in a skillet over medium heat. Add your finely chopped onion and sauté until translucent. Then, stir in the minced garlic and cook for another minute. This mixture will create a flavor foundation.

Once the potatoes are done, drain them in a colander. Return them to the pot over low heat to evaporate any remaining moisture. Then, grab a potato masher and start mashing!

To your mashed potatoes, add the sautéed onions and garlic, along with the heavy cream, whole milk, sea salt, black pepper, sour cream, and fresh thyme leaves. Stir until the mixture is smooth and creamy. Taste and adjust seasoning as needed.

Finally, serve your Texas Roadhouse mashed potatoes hot. A pat of butter on top makes for a heavenly finish.