How to Make It
Stir together evaporated milk, wine, and garlic in a 1 1/2-quart slow cooker. Cover and cook on high, until hot, about 10 minutes.
Meanwhile, toss together Gruyère, Swiss, and cornstarch in a medium bowl. Add cheese mixture and lemon juice to cooker. Cover and cook, stirring every 5 minutes until cheese is just melted, about 45 minutes. (Be careful not to overcook or fondue will seize.)
Reduce cooker to warm. Sprinkle with pepper. Serve with smoked sausage, roasted vegetables, cubed bread, apple slices, and grapes.