Lightly brown onions in the oil and remove with a slotted spoon. Reserve.
Step2
Pat the meat dry between two paper towels and brown on all sides in the same pot without crowding.
Step3
Sprinkle the browned meat with flour, salt, and pepper.
Step4
Add the wine, garlic, stock, tomato sauce, and herbs.
Step5
Over medium-low heat, bring the mixture to a simmer and then cook tightly covered for 2 or more hours or until the meat is fork tender. Add onions after 1 hour.
Step6
Wipe the mushrooms with a damp cloth and trim off the stem ends. Quarter the mushrooms if they are large and leave the small ones whole.
Step7
Heat the butter and remaining part of the oil in a large skillet and lightly saute the mushrooms for about 4 minutes. Set aside.
Step8
When the meat is done, skim off the fat and add the mushrooms.
Step9
If the sauce is too thin, combine 2 Tbsp flour with 1/2 cup water and whisk the mixture into the boiling pot.