In a large saute pan, melt 2 tablespoons of butter over a high heat. Add the mushrooms so that they sear, and then move them to a separate bowl before they expel their juices. If the juices do start to expel, add them in the bowl as well. Set aside for later. It might be helpful to do this in two batches.
Either return the pan to the burner (if it’s a very large pan), or swap it for a larger stew pot, and set the heat to medium-low. Add the olive oil and onion to the pan, stirring occasionally for 5 minutes, until translucent.
Add garlic and stir for a minute or two, until fragrant. Then add the carrots, celery, thyme, and rosemary. Cook for another 5-10 minutes, stirring occasionally, adding a bit more olive oil if it starts to look dry.
Bring heat up to medium and add the cup of wine. Allow it to cook down to about half, roughly 4-5 minutes, then stir in the tomato paste.
Add the mushrooms back into the pan, along with the 2 cups of vegetable stock, salt, and pepper (and pearled onions if you’re using them), and bring to a simmer for about 15-20 minutes.
As the stew simmers, melt two tablespoons of butter in the microwave. Add the two tablespoons of flour to the melted butter, stirring it into a homogeneous paste. Quickly whisk the paste into the simmering stew.
Stir regularly as the stew thickens, about 10-15 minutes. Once the stew has thickened nicely, serve immediately over a bed of quinoa.
Make the Quinoa
Combine two cups of vegetable stock with 1 cup of quinoa and bring to a boil in a covered pan. Once it reaches a boil, reduce heat to low and allow it to slowly simmer for about 25 minutes or until all of the liquid has been absorbed. Or just follow the package instructions.