On a clean surface, make a well with the flour. Break all 4 eggs into the well and start stirring the eggs while incorporating more and more of the flour until a dough is formed. Add a tablespoon of olive oil, incorporating it into the dough. If the dough is dry add more oil. If it gets too sticky, add a little more flour. Form the dough into a smooth ball and cover with plastic or a clean kitchen towel. Let it rest for 20 minutes. 

While the dough is resting, get started on the filling. In a pan, brown the sausage. Then add the salt, garlic, thyme and chopped sage, and walnuts. Continue to cook for another three minutes. Remove from heat and stir in the Pecorino Romano. Set aside to cool. 

Return to the dough. If you have a pasta roller, take smaller sections of your dough ball and start rolling out sheets of dough. Get it about as thin as you can without it tearing, about a 2 on a pasta rolling machine. If you don’t have a pasta machine, no worries. Lightly flour your work surface and pull a section of the dough off of your big dough ball and roll it out on the surface using a rolling pin or heavy bottle such as a wine bottle. Roll the dough sections out as thin as you can get them without them tearing and then cut the sheets to be about 4-5 inches wide. They can be as long as you’d like. Cover the larger dough ball with your plastic or kitchen towel to keep it from drying out as you roll out sheets.

Now that you have some dough sheets, get a small bowl of water to wet your fingers. Bring your filling over to your work station as well. Starting at the top of the sheet, place a teaspoon of the filling on the left side of the dough sheet leaving enough dough around the sides of your teaspoon full of filling. Repeat this, moving down the sheet of dough until you are out of space. Then wet your finger tips and spread a bit of water down the middle of the dough sheet and in between each spoonful of filling. Then wet the left side. Work quickly as to not allow the dough to dry. Then fold over the right side (the side without filling) over the filling side and press down around the filling, sealing it into the dough. Then, with a knife or pizza cutter, cut the dough between each filling section to give yourself individual raviolis. Take a fork and press around the edges to give it some texture and extra seal. Set the ravioli on a tray covered by parchment paper and take the same steps with the rest of the dough and filling.

Once your ravioli is assembled, fill a large pot half to 3/4 full of water. Salt it and bring to a boil. Drop a few ravioli into the boiling water and cook until they float to the top and are cooked through. Using tongs or a spider strainer, remove the cooked ravioli and add more. Continue until they are all cooked through. Save the water. You’ll need some for the sauce.

Now make your brown butter sauce. In a medium saucepan, melt the stick of butter on a medium low heat. Now, keep an eye on your butter, stirring occasionally to make sure it doesn’t burn. The white bits of fat will start to turn to brown bits. As that is happening, add the sage and the salt. Allow the sage flavor to infuse the butter, so cook it for about a minute or two, stirring to make sure that nothing burns. Your butter will develop a bit of a nutty flavor/smell. Then add about 1/4 cup of pasta water. Cook the mixture down for about 3-5 minutes.

Plate the ravioli and drizzle the butter sage sauce over it. Top with any other fresh herbs such as more sage and/or parsley.