In a large (12 inch) skillet, heat the olive oil over medium-high heat.Add the onion and cook until softened, about 3 to 5 minutes. Stir in the garlic.
To the skillet, add the rice and cook for 3 minutes, stirring often to avoid burning. Add the wine into the skillet and stir, cooking until almost completely absorbed.
Pour the rice into the slow cooker.Stir in the heated broth, lemon juice, lemon zest, salt, and black pepper.Cover the slow cooker and cook on high for 90 minutes.