Preheat oven to 350 degrees.

Rinse, pat dry and slice fresh mushrooms (makes about 5 ½ cups); set aside.

Pound veal between 2 pieces waxed paper until thin.

Combine lemon juice, salt and black pepper.

Brush on both sides of veal.

Dredge meat with flour, carefully shaking off excess.

In a large skillet heat 2 T.

of the oil and 2 T.

of the butter.

Add veal, a few pieces at a time.

Cook over moderate heat until brown, about 3 minutes on each side.

As the meat browns place in a shallow ovenproof casserole.

Add additional oil and butter to skillet as needed, reserving 4 T.

of the butter to be added when all the meat is browned.

To the hot butter stir in reserved mushrooms and onion; sauté until golden, about 5 minutes.

Remove mushrooms and onion to a bowl.

Stir Marsala and broth into skillet; bring to the boiling point.

Reduce heat and simmer, uncovered, for 2 minutes, stirring to loosen particles on bottom of pan.

Add tomatoes, tarragon and reserved mushroom mixture; simmer for 2 minutes.

Remove from heat; season with additional salt and pepper if necessary.

Pour over meat.

Cover.

Bake for 20 to 30 minutes.