Bloom the 1/2 envelope of gelatin in 1/4 cup cold water. In the mean time warm the soup and milk in a small pot. Add gelatin to soup mix. Bring to a boil and stir until gelatin is dissolved.
Lightly grease a 6 inch round cake pan with olive oil. Pour soup mix into the pan and refrigerate until set, about 2-3 hours.
Slice mushrooms. Heat olive oil in a pan and brown the mushrooms. Set aside.
In a large pot bring to a boil the green beans in water. Simmer 8-10 minutes. Drain and rinse with cold water to stop the cooking process. Cut green beans down to 2 inches. Mix with tomato.
Bloom the 1 envelope of gelatin in 1/4 cup cold water. In the mean time bring to a boil the chicken stock. Add gelatin to stock and stir until gelatin is dissolved. Let cool.
Slice onion 1/4 in thick. Mix flour, salt and pepper in a bowl. Heat olive oil in a frying pan. Dip the onion rings in the flour and fry them on medium heat until brown, about 10 minutes. Set aside.
Place the green beans on top of the set soup mix. Layer mushrooms on top of green beans. Just cover veggies with cooled stock and refrigerate until set, about 8 hours to overnight.
To unmold, pass a knife around the perimeter of the mold. Fill a pot with hot tap water. Place aspic mold in the hot water for 10seconds.
Place a plate on top of mold and flip in one quick move. Lift mold gently.