Saute mushrooms in 1/4 cup olive oil until just tender
Drain the mushrooms toss with lemon juice and transfer to a bowl
Add 2 Tbsp oil to the skillet and cook the onions until they begin to turn tranlucent
Add the garlic and saute for a few more minutes until the onions are golden but not browned
Stir in the pepper thyme marjoram and bay leaves and saute for another minute
Drain the tomatoes and reserve 1/3 cup of juice Coarsely chop the tomatoes and mix them into the onions along with the reserved tomato juice vinegar cayenne salt and sugar
Simmer on low heat covered for 20-25 minutes stirring occasionally
Allow the marinade to cool for serveral minutes and then pour it over the mushrooms
Chill covered for at least 12 hours Bring the mushrooms to room temperature before serving