- 1 tablespoon unsalted butter or margarine
- 1 tablespoon olive oil
- 1 onion, thinly sliced
- 2 large garlic cloves, peeled and crushed
- 2 (28 ounce) cans whole peeled tomatoes
- 1 cup water
- 1 tablespoon sugar
- 1 teaspoon salt, plus more to taste
- freshly ground black pepper to taste
- 1 pinch red pepper flakes
- 1/4 teaspoon celery seed (I didn’t have celery seed, so I used celery salt)
- 1/4 teaspoon dried oregano
- Heat butter and olive oil in a large saucepan over medium-low heat and cook onion and garlic until onion is soft and translucent, about 5 minutes. Add tomatoes, water, sugar, salt, pepper, red pepper flakes, celery seed, and oregano. Bring to a boil. Reduce heat, cover, and simmer for 15 minutes.
- Remove from heat and puree with an immersion blender. Reheat soup until warm and season with more salt and pepper if desired.