If using tinned lentils, Heat oil in a large saucepan over medium-high heat. Add onion and garlic and cook, stirring, for 3 to 5 minutes or until onion is translucent. Add tomatoes, stock, carrot, celery, salt and pepper and bring to the boil. Reduce to a simmer and cook covered for 1 hour. In the last 20 minutes, add the lentils and quinoa.
If using dry lentils, Heat oil in a large saucepan over medium-high heat. Add onion and garlic and cook, stirring, for 3 to 5 minutes or until onion is translucent. Add tomatoes, stock, carrot, celery, lentil, salt and pepper and bring to the boil. Reduce to a simmer and cook covered for 1 hour. In the last 20 minutes, add quinoa.
Notes
Lentils
1 cup if using dry lentils or 1 14 oz/400 gram tinned lentils
Storing Tips
This soup will keep in the freezer for 2-3 months. I like to freeze into the desired portion sizes and then when needed, take out of the freezer and thaw out before heating to eat.