Adapted from www.marthastewart.com
Makes 3 quarts
1 tablespoon butter
1 tablespoon olive oil
1 large onion (about ½ pound), coarsely chopped
2 carrots (about ¼ pound), coarsely chopped
2 parsnips (about 1 pound), coarsely chopped
1 celery stalk, coarsely chopped
1 large bunch (about 1 ½ pounds) red and/or green Swiss chard
Several sprigs fresh thyme
Several sprigs fresh flat-leaf parsley
1 dried bay leaf
In a medium stockpot over medium high heat, melt butter and olive oil. Add onion, and cook, stirring, until caramelized, about 8 minutes. Add carrots, parsnips, and celery; cook until tender, about 15 minutes.
Wash and drain chard thoroughly. Chop into 1” pieces. Add to the vegetable mixture. Then add 3 quarts plus 2 cups cold water, thyme, parsley, and bay leaf. Bring to a boil, reduce heat, and let simmer about 1 hour; liquid should be highly flavored.
Remove from heat and strain stock through a fine sieve, pressing on vegetables to extract juices. Discard vegetables. Stock can be refrigerated for 3 to 4 days or frozen for up to 3 months.