First, chop up all of your veggies and garlic. Heat your oil in pot, add your carrots, and saute until slightly tender. Then add in the celery, leek, potatoes and garlic. Pour in your clam juice and diced clams, along with their liquid, and simmer on medium-high heat until potatoes are fork-tender.
While this simmers, make a roux in a medium saucepan. Start by melting a 1/2 cup of butter, then add a 1/2 cup flour and whisk for a minute. Then, whisk in half and half until all ingredients are combined, stirring constantly throughout the process.
Once the roux is ready and potatoes are fork tender, pour the roux into the soup, stir until fully mixed, and simmer for a few minutes.
Notes
Clam chowder is best enjoyed with oyster crackers and a garnish of chives.
It's also delicious when eaten out of a bread bowl.