Ingredients
Serves 4-6
2 onions, sliced
2 tbsp olive oil
4 russet potatoes, thinly sliced
5 tbsp unsalted butter
3 tbsp all-purpose flour
1 tsp sea salt
2 cups whole milk
2 cloves garlic, minced
2 tbsp rosemary, finely chopped
2 tbsp thyme, finely chopped
2 cups shredded gruyere
Preparation
