1 small mushroom, sliced
1/2 teaspoon salt
1/2 teaspoon dried basil
3/4 cup beef bouillon granules
1/2 cup olive oil
1 egg
1 tablespoon lemon juice
1 tablespoon Worcestershire sauce
1 1/2 tablespoons ketchup
2 tablespoons soy sauce
2 tablespoons garlic powder
Season mushroom slices with salt and basil; remove flesh. Cut mushrooms in half lengthwise. Place mushroom slices in a medium bowl. Add bouillon, olive oil, egg, lemon juice, Worcestershire sauce, ketchup, and garlic powder; mix well. Place mushroom slices in a second medium bowl.
Pour in remaining olive oil and whisk well.