French Leek and Onion Soup

1 tbs canola oil
2 medium sweet onions, sliced
2 small leeks, white and light green parts only, sliced
2 tbs tomato paste
2 cups Pinot Noir or Merlot
6 cups home-made beef stock
1 tbs brown sugar
1 tsp balsamic vinegar
kosher salt/fresh ground pepper
8 slices French baguette, toasted
¾ cup grated old white cheddar
Add oil to a large soup pot over medium heat. Stir in onions and leeks to coat. Cook, stirring occasionally and watching carefully to prevent the onions from scorching. Continue to stir often, scraping the bottom of the pot with a wooden spoon, until onions are a deep brown. Stir in tomato paste and continue cooking, uncovered, scraping the bottom of the pot often, for about 5 more minutes.
Add wine. When it begins to simmer, reduce heat to medium-low. Simmer until reduced by 90%. Add beef stock. Bring up a boil, then simmer for about ½ hour. Add sugar, vinegar and seasoning.
Ladle hot soup into 4 French Onion Soup bowls. Top with toasted slices of baguette and grated white cheddar. Place bowls on a baking sheet and into a 450F oven until cheese is bubble and just beginning to brown.