01 - Mound flour on a clean work surface and create a well in the center. Crack eggs into the well and add salt. Gradually incorporate flour into eggs using a fork, then knead by hand for 8 to 10 minutes until smooth and elastic. Wrap dough in plastic and let rest for 30 minutes.
02 - Heat olive oil in a skillet over medium heat. Sauté onion until softened, about 3 minutes. Add garlic and mushrooms; cook until mushrooms release moisture and turn golden, approximately 5 minutes. Remove from heat and stir in chicken, Parmesan, parsley, pepper, and salt. Allow mixture to cool completely.
03 - Divide rested dough into two equal portions. Roll each piece into a thin sheet about 1/16 inch thick using a pasta machine or rolling pin.
04 - Place small mounds of filling, about 1 teaspoon each, 1 inch apart on one dough sheet. Lightly brush edges with water, cover with second sheet, and press firmly around each filling mound to seal. Cut into individual squares and crimp edges with a fork to ensure closure.
05 - Heat olive oil in a saucepan over medium heat. Add sliced garlic and sauté until fragrant, about 1 minute. Pour in crushed tomatoes and add sugar, salt, pepper, and oregano. Simmer uncovered for 15 to 20 minutes until slightly thickened. Stir in fresh basil just before serving.
06 - Bring a large pot of salted water to a rolling boil. Gently add ravioli and cook for 3 to 4 minutes until they float to the surface. Remove carefully with a slotted spoon.
07 - Transfer cooked ravioli to serving plates. Spoon warm tomato sauce over the top and garnish with grated Parmesan cheese and fresh basil leaves. Serve immediately.