German-Style Fried Potatoes - cooking recipe

Ingredients

4 lbs unpeeled medium-size red potatoes
4 1/2 tablespoons olive oil
3 tablespoons malt vinegar or 3 tablespoons white wine vinegar
1 tablespoon Dijon mustard
6 6 tablespoons rendered bacon fat or 6 tablespoons olive oil, divided
coarse kosher salt
6 tablespoons lager beer, divided
2 1/2 cups finely chopped red onions, divided
1/3 cup fresh chives (green parts only) or 1/3 cup green onion, chopped (green parts only)

Preparation

Cook potatoes in large pot of boiling salted water until just tender when pierced with sharp knife, about 25 minutes.
Drain.
Refrigerate potatoes overnight.
Cut potatoes into 1/2-inch cubes (do not peel).
Whisk oil, vinegar, and mustard in small bowl to blend for vinaigrette.
Heat 3 tablespoons lard in each of 2 large nonstick skillets over medium-high heat.
Add half of potatoes to each skillet; sprinkle with coarse salt.
Saute until potatoes begin to brown, stirring frequently, about 7 minutes.
Add 3 tablespoons beer, then 1 1/4 cups red onions to potatoes in each skillet; cook until beer evaporates, stirring occasionally, about 1 minute.
Reduce heat to medium and saute until potatoes are brown around edges, about 5 minutes.
Pour half of vinaigrette over potatoes in each skillet and toss to coat.
Remove from heat.
Season to taste with salt and pepper.
Transfer all potatoes to large bowl.
Sprinkle with chives.