Combine rice flour, starch, xanthan gum and salt in the bowl of a stand mixer. On medium speed, slowly add oil and warm water. If the dough is too sticky, add more flour, if it is too dry and not holding together well, add more water.
Cover dough with plastic wrap and let rest in the fridge for 30 minutes.
For the filling
Puree spinach and smoked tofu in a food processor. Add garlic clove and salt to taste and set aside.
For the sauce
Sauté mushrooms and onions in olive oil until nearly all of the water has evaporated.
Add soya cream and vegan sour cream and cook on medium heat for about 5-10 minutes.
Season with salt and pepper to taste.
Making the Ravioli
Once the dough has rested, divide it in quarters for easier rolling. On a floured surface, roll out sections of the dough until about 1/8 inch thick.
Place about 1/2 tsp of filling two inches apart from each other on the sheet of pasta.
Moisten the dough around the filling mounds, place another sheet of pasta on top and gently press down around the outside edges of the dough to seal – try to get all of the air bubbles out.
Cut your dough into squares or use a cookie or ravioli cutter.
Keep the ravioli separated from each other to avoid them sticking together.
Bring a large pot of salted water to boil. Boil your ravioli for about 6-9 minutes, until al dente, carefully remove with a slotted spoon and place on a plate.
Drizzle with sauce and garnish with fresh parsley.