Add butter to skillet; cook over medium until melted, about 1 minute.
Add onion, and cook, stirring occasionally, until softened, 3 to 5 minutes.
Add minced garlic, and ¼ teaspoon each of the salt and pepper; cook, stirring occasionally, until fragrant, about 1 minute.
Stir in rice to coat in onions and garlic.
Add wine, and cook, stirring often, until mostly evaporated, about 1 minute.
Add enough warm stock (about 2 cups) to cover rice, and bring to a low simmer over medium-low.
Continue to cook, stirring occasionally, reducing heat as needed to maintain a low simmer, and adding more stock as needed to keep rice covered, until rice is just tender and most of the liquid has absorbed, 20 to 30 minutes. (You should use all the stock.)