2 Tbsp olive oil
2 baking potatoes, very thinly sliced
1/2 yellow onion, very thinly sliced
2 cloves garlic, minced
1 1/2 Tbsp vegan butter
1 Tbsp flour
1/3 cup unsweetened almond milk
1 Tbsp nutritional yeast
1 heaping Tbsp vegan sour cream (I used Tofutti brand, available at Whole Foods)
1 sheet frozen puff pastry, defrosted for 1 hour
sliced scallion for garnish
Preheat oven to 350 degrees. In a large skillet over medium heat, add olive oil, potatoes, and onions, and saute occasionally for about 6-8 minutes or until the potatoes are slightly tender. Sprinkle with salt and add the garlic halfway through. Then, in a large, deep skillet over medium low heat melt butter until it starts to fizz slightly. Add flour and whisk constantly until smooth. Pour in almond milk and continue to whisk, raising the heat to medium high. Bring the mixture to a slight simmer to thicken and keep whisking. Once thickened up a bit, add nutritional yeast, a sprinkle of salt, and sour cream. Whisk to incorporate, and then fold in potato and onion mixture to coat in the creamy sauce. Turn heat to low and let sit while you prepare the puff pastry.
On a baking sheet, place puff pastry sheet in the center and use a fork to lightly prick the pastry all around the center, leaving a 1 inch border unpricked. Place in the oven for 2 minutes. Remove from oven and spread creamy potato mixture evenly in the center of the pastry leaving a border. Place back in the oven and bake for another 15 minutes or until the edges are golden brown. Garnish with scallions and serve immediately.