Rinse lentils and pick through to remove any debris.

Heat vegetable oil in a large pan over medium heat.

Add chopped yellow onions, celery, and garlic to the pan.

Cook, stirring occasionally, until the onion is soft and translucent.

Stir in chicken stock, tomato puree, lentils, chopped tomatoes, and chopped carrots.

Bring the soup to a simmer.

Reduce heat and simmer for about 45 minutes, or until the lentils and carrots are tender.

While the soup simmers, cook the sausages in a separate pan.

Cook sausages until browned all over and cooked through.

Drain the cooked sausages on absorbent paper to remove excess grease.

Slice the sausages into bite-sized pieces.

Add the sliced sausages to the soup.

Cook uncovered until the soup is heated through.

Add pepper to taste.