Corned Beef and Cabbage Chowder

Name: Corned Beef and Cabbage Chowder
Ingredients: 1 tablespoon olive oil (extra light ); 1 medium yellow onion (diced (about 1½ cups)); 2 to 3 medium carrots (sliced (about 3/4 cup)); 2 to 3 short celery stalks (sliced (about 3/4 cup)); 2 teaspoons kosher salt (more or less to taste); 1 large garlic clove (minced); 2 pounds russet potatoes (chopped); 2 cups chopped cabbage; 1 bay leaf; 1 quart (4 cups) low-sodium chicken broth; 1/2 cup heavy cream; 1/2 cup irish stout beer (like Guinness); 2 cups leftover cooked corned beef (chopped); 1 tablespoon flour; snipped chives (for sering (optional)); rye croutons ((optional))