Wash and drain the lentils, carefully picking through them to take out any pebbles.
In a 3-quart saucepan, heat the 6 tablespoons oil until just smoking. Add the onions and sliced garlic. Cook until softened but not brown, about 6 to 8 minutes. Add the lentils and the hot chicken stock. Bring the liquid to a boil. Lower then heat and simmer for 25 to 30 minutes, keeping the level of the liquid just over the lentils by periodically adding more water. Add the pasta shells during the last 6 minutes of cooking. Season, to taste, with salt and pepper.
In the meantime, preheat the grill or broiler. When the soup is ready to serve, grill or toast, slices of the bread until golden brown, about 2 minutes per side. Rub each slice with a cut garlic clove.
Ladle the soup into warm bowls. Place a slice of garlic bread on top of each soup serving. Drizzle the bread and the soup with the chili oil and serve immediately.
2 cloves garlic, sliced thin
2 tablespoons chili flakes
1/4 cup extra-virgin olive oil
2 teaspoons salt
1 teaspoon cracked black pepper
In a small hot saute pan, add extra-virgin olive oil and garlic. Saute until golden and add chili flakes and salt and pepper. Cook for 2 minutes. Remove from the heat and let infuse.