1   medium onion, finely chopped
1  tablespoon extra-virgin olive oil
2  tablespoons tomato paste
1  pound Yukon Gold, cut into 3/4-inch cubes
3  vegetable bouillon cubes, dissolved in 1 cup of boiling water
1/4  teaspoon crushed red pepper
1  cup tubetti pasta
1  large tomato, cut into 3/4-inch dice
1  tablespoons finely chopped Italian parsley

1  tablespoon finely chopped basil

1 tablespoon finely chopped sage
Salt
1/2  cup sour cream

DIRECTIONS
  In a saucepan, cook the onion in the oil over moderate heat, stirring, until just softened, about 5 minutes. Stir in the tomato paste and cook for 1 minute. Add the potatoes, bouillon, crushed pepper and 5 cups of water. Cover and bring to a boil. Stir in the pasta and cook until al dente, about 10 minutes. Stir in the tomato and herbs and cook for 1 minute longer. Season with salt and serve with sour cream.