4 Tablespoons (1/2 stick) unsalted butter
2 Tablespoons olive oil
1 medium onion, chopped
1 medium carrot, finely diced
course sea salt and fresh black pepper
splash of red wine vinegar (just over 1 Tablespoon)
1/4 cup all-purpose flour
3 Tablespoons tomato paste
1 dried bay leaf
2 cans (14 1/2-ounces each) low sodium chicken broth
2 cans (28-ounces each) whole peeled tomatoes in juice (with basil if available)
1/2- 3/4 cup whole milk or cream