Slice onions. Peel and crush garlic.
In a large skillet, heat the oil. Once the oil is hot, brown the steaks on both sides.
Add the crushed garlic and sliced onions. Saute with the steaks for 4-5 minutes, or until onions become transparent. Add drained mushrooms and mix in.
In a small bowl, combine tomato paste with 2 cans worth of water.
Pour tomato sauce over the steaks, onions and mushrooms. Combine well. Stir in tarragon, and a dash of salt and pepper.
Once it starts to splatter, reduce heat to medium-low.
Cover and cook for 10-15 minutes, or until steak has cooked through.
Warm veggies and mashed potatoes.
Serve Mushroom Swiss Steak with veggies and potatoes.