- To make the pasta, put flour and salt in bowl of a food processor. Pulse briefly to combine. Add eggs and process for 30 to 60 seconds, or until dough forms a rough ball. If dough appears dry, add water one teaspoon at a time. If it is smearing along sides of mixer, add one tablespoon flour. Transfer to a lightly floured surface and knead for one minute. Wrap in plastic wrap and let rest in refrigerator for 30 minutes.
- To make the filling, mix ricotta, burrata, sundried tomato purée, one-quarter teaspoon pepper and nutmeg in a medium bowl. Add salt as needed.
- Roll out pasta to thinnest setting according to pasta machine instructions. Cut into four 22-inch long sheets.
- To assemble ravioli, lay out a sheet of pasta and dollop one half tablespoon mounds of filling in two lines, two inches apart. Brush egg yolk around filling. Lay another sheet of pasta directly over filling and use your fingers to press out any air pockets. Using a round two-and-a-half-inch cutter, or larger, cut out ravioli around filling. Remove excess pasta and press edges closed with your fingers. Repeat with remaining sheets of pasta and filling. Place on a rimmed baking sheet that has been sprinkled with semolina or cornmeal. Sprinkle ravioli with additional semolina to avoid sticking. Chill until ready to cook.
- To make sauce, sauté mushrooms and asparagus until tender. Add thyme, tomatoes and season with salt and pepper. Add butter and remove from heat swirling to emulsify and coat.
- To assemble, bring a large pot of salted water to a boil. Cook ravioli until pasta is tender and filling is hot. Place them in bowl and top with mushroom sauce. Garnish with grated parmesan cheese.
Chef Note: You can use store-bought wonton wrappers instead of making pasta dough; you’ll need two packages of wrappers. In step four, lay out six wrappers on a clean dishtowel and brush with egg yolk. Mound one half tablespoon filling on each. Cover with another wrapper, pushing out air before sealing well with your fingers. Repeat with remaining wrappers and filling.