Clean and finely chop the mushrooms. Heat oil in a pan. Fry the mushrooms until golden brown. Drain tomatoes and dice finely, except for 1/2 for garnishing. Stir the mushrooms, except for a teaspoon for garnishing, with the diced tomatoes into the base cream.
Cut 1/2 tomato into strips. Garnish the dip with the tomato strips and remaining mushrooms.