Make the pasta dough: Put the flour in a large bowl and add the eggs and salt. Mix with until you have a dough and then knead until there is no flour left in the bowl.
Turn the dough out and knead until the dough is smooth then shape into a ball and cover in plastic film. Leave to rest in the fridge for 30 minutes.
Make the filling while it rests: In a saucepan combined the mushrooms, butter, onions, and garlic and cook them down until the mushroom completely brown.
Pulse the filling finely with a stick blender or in a regular blender.
Let cool completely then mix in the ricotta, thyme, and seasoning.
When the dough is ready, flour a work surface and divide dough in to 4 piece, roll the dough as thin as possible.
Use a circular 2" cookie cutter to cut circles from the dough OR cut in to 2-3" squares with a sharp knife.
Add about 1/2 teaspoon of filling to the center of the cut dough circle/suare, moisten the edges with water and fold the dough over creating a seal around the filling.
Pick up the corners and bring them toward each other then tuck one corner behind the other and press together.
Place finished tortellini on parchment paper. Repeat until all the dough is used up.
Cook tortellini in salted boiling water approximately 4 minutes until just tender.