2 tablespoons unsalted butter
1/2 medium yellow onion, thinly sliced
1/2 teaspoon crushed coriander seeds
1 garlic clove, finely chopped
1 1/2 pounds green heirloom tomatoes, cored and roughly chopped (about 4 cups)
1 cups chicken or vegetable stock or water or combination
1 1/4 teaspoons kosher salt, more to taste
Freshly ground black pepper
2 ounces sliced bacon (*can be omitted and extra virgin olive oil or more unsalted butter can be substituted to toast the ciabatta)
2 slices ciabatta, cut into 1/2-inch cubes
1/3 cup crème fraîche (optional)
1 tablespoons chopped fresh basil
1 tablespoon honey, or to taste.
Melt butter in a medium pot over medium-high heat. Add onion and cook, stirring occasionally, until translucent, about 5 minutes.
Add the coriander to pot along with garlic and sauté for 3 minutes longer.
Stir in tomatoes, stock, salt and pepper. Bring to a boil; immediately reduce heat to medium-low and simmer soup about 30 minutes.
While the soup is simmering, fry bacon in a skillet until crisp. Use a slotted spoon to transfer bacon to a paper-towel-lined plate. Return skillet to medium heat. Add ciabatta to bacon fat in pan and toss to coat well. Toast, tossing occasionally, until croutons are golden, about 5 minutes. Set aside and try to resist eating all the croutons.
Using an immersion blender (or puréeing in batches in a regular blender), purée soup until smooth.
Return soup to medium heat and stir in crème fraîche if desired, basil and honey. Heat up, 1 to 2 minutes. Taste and add more salt or honey or both. Ladle soup into individual serving bowls; crumble bacon over top and garnish with croutons.