• All ingredients ready? Let's begin!
  

Pasta

• On a flat, clean work surface, place the flour in a tall mound. Make a well in the center of the flour that is deep enough to contain the eggs. Crack the eggs into a bowl. Carefully pour the eggs into the flour well.
  
• Working slowly, use a fork to mix the eggs in the well. Then, incorporate the flour into the eggs from the perimeter. This is a little messy but worth the effort. Once the flour is mostly combined, use your hands to gather the dough into a ball. Knead the dough with the heels of your hands until it is smooth and elastic, about 5 minutes. Wrap the pasta dough in plastic and refrigerate it for 30 minutes while you prepare the pesto and filling.
  

Pesto

• In a large heavy-bottomed skillet over medium heat, toast the walnuts until just fragrant and lightly browned, approximately 3 minutes, stirring occasionally. Transfer the walnuts to the bowl of a food processor along with the garlic. Reserve the skillet to cook the sausage filling. Pulse until the walnuts are finely ground.
  
• Add the basil and spinach to the food processor and pulse until the greens are minced.
  
• Add the salt, pepper, parmesan, and lemon juice to the processor and pulse again until very well combined, scraping down the sides of the bowl with a silicon spatula or wooden spoon if needed.
• Stream the olive oil through the hole in the processor lid while the machine is running. Do this slowly until you have a smooth paste. If the pesto seems too thick, thin it with a little bit of water.
  
• Place the pesto in a small mixing bowl and set this aside or refrigerate until ready to use. Reserve the food processor for the next step. There is no need to wipe the bowl of the processor out.
  

Sausage Filling

• In the same skillet that you toasted the walnuts in over medium-high heat, warm the olive oil. Add the sausage to the pan and break it up with a wooden spoon. Cook for about 6 minutes.
  
• Add the shallot, garlic, and mushrooms to the sausage and continue to cook until the sausage is completely browned and the shallots are soft, approximately 6 minutes longer.
  
• Using a slotted spoon, remove the sausage filling to a paper towel-lined platter and allow it to cool.
  
• Once the sausage is cool, place the mixture in the bowl of the food processor and pulse until minced. Add the egg and pulse again just to combine. Set this aside while you prepare the ravioli.

Assembly & Cooking

• Remove the pasta dough from the refrigerator. Lightly flour your work surface and place the ball of dough on the surface. Cut the dough in half and rewrap one half in the plastic. Set that aside.
  
• Using a rolling pin, roll out one half of the dough to about 1/8-inch thickness. Slice the dough into widths that will fit into your pasta roller. Set your pasta roller to the widest setting and pass the dough sheets through the roller.
  
• Fold the pasta into thirds like a letter and pass it through the roller another time. Do this step 3 or 4 times.
• Continue this process, turning the setting of the roller smaller and smaller with each pass. You want the sheets of dough to be thin enough to almost see your hand through it. Place the pasta sheets on a lightly floured sheet pan and repeat with the other half of the dough.
  
• If using a ravioli press, place a sheet of pasta loosely over the press and push down the centers to form indentations. Fill the centers with a spoonful of the sausage mixture. Place another sheet of pasta over the filled sheet. Using a rolling pin, roll the top sheet to fuse and close the ravioli. Flip the ravioli out onto your work surface and slice between each filled portion to separate them. Transfer the ravioli to a lightly floured sheet pan.
  
• If you are using a ravioli cutter stamp, place a sheet of pasta on your lightly floured work surfaces. Place spoonsful of filling in 2 lines on the sheet, about 1/2-inch apart. Top the filling loosely with another sheet of pasta and press down with your fingers around the filling to encase each spoonful. Use your stamp or a rolling ravioli cutter to make individual ravioli. Place these on the floured sheet pan.
  
• Bring a large pot of water and 2 Tbsp of kosher salt to a boil over medium-high heat. Carefully drop the ravioli into the water and cook until al dente, approximately 1-1/2 to 3 minutes.
  
• Using a spider or slotted spoon, transfer the pasta to a serving bowl. Spoon the pesto over the pasta and toss gently to coat all of it. Serve while warm.