1. Sauté the onion, garlic, and chillis with 2 tbsp of olive oil. Add the pumpkin and cook until they are soft; add a splash of water if necessary. Add chards and continue sauteing until tender. Let the chards cool a little bit and add cheese. Season with salt and pepper.
Heat your oven to 350 F (180C). In a large bowl, beat the eggs and add milk, yogurt, olive oil. Mix well.
Cut the yufka sheets into 10 pieces. After you brush the oven pan with olive oil place the first yufka in your dish. Brush the yufka slightly with the yogurt and egg mixture and repeat this process 3 times. Pour half of the chard mixture over the last yufka and distribute evenly. Put another yufka on top and brush with the yogurt mixture. Repeat this 3 times and pour the rest of the chard mixture again and distribute evenly. Cover with the last 2 yufka sheets. Brush the last yufka with the mixture generously. Cook for 30-35 minutes until your borek is golden.