Set the oven to 180 degrees and run it.
Wash, rinse the chard in cold water. Chop them in finger size. Chop the onions thinly, in half moon shape.
Take a pan on the stove. Add butter and 1 tbsp olive oil. When the butter is melted over medium heat, sautée the onions for 4 minutes.
Add the chard. Sautée until chards softened, around 4-5 min. Add garlic powder and a pinch of salt & black pepper. Mix. Turn the fire off and let it stand on the side.
Grate half of the goat cheese. You will use the other half for the salad. (You can grate or cut into cubes.)
Place the long edge of one puff pastry dough on the long edge of the other one. And make them stick together, with your finger. With the help of rolling pin or using stretch film/foil like rolling pin, make puff pastry slightly thinner.
Paste the remaining 2 puff pastry in the same way. So you'll have two pies.
Place the baking paper in the ovenware/tray and place 2 pies side by side. Make marks on all sides of the puff pastry with the help of a fork.
Place the chard mix in the middle of the pies. But leave 2-3 cm space at the edges. Sprinkle the goat cheese you've grated.
Close the edges of the puff pastry that you left blank. (Like pizza edge)
Take the yellow part of the egg into a bowl and whisk. Rub it with the help of a brush or your. (to the edges)
Bake at 180 degrees for 15-20 min. until the dough gets crispy.
Wash and rinse greens in cold water. Wash radishes and slice them finely without peeling.
Take greens and radishes in a mixing bowl, add 1 tbsp olive oil, a pinch of salt & pepper and stir.
After placing goat cheese on the salad, you can serve it with Rustic Tart.