1

Combine the mayonnaise and half of the minced garlic in a small bowl; cover and refrigerate until the flavors blend, at least 15 minutes or up to 2 hours.

2

Preheat the broiler. Place the bread rounds on a baking sheet; spray lightly with olive-oil nonstick spray. Spread the remaining garlic on top of the rounds. Broil 5 inches away from the heat until golden and fragrant, 2–3 minutes.

3

Heat the oil in a large nonstick saucepan over medium-high heat. Add the onion and cook, stirring occasionally, until golden, 7–10 minutes. Add the broth, wine, lemon, parsley sprig, and thyme sprig; bring to a boil. Reduce the heat and simmer, covered, until the flavors blend, about 10 minutes. Discard the lemon, parsley, and thyme.

4

Stir the spinach into the broth mixture and simmer, covered, until the spinach just begins to wilt, about 1 minute. Stir about 1⁄2 cup of the hot broth into the mayonnaise mixture; whisk until smooth. Return the mayonnaise mixture to the saucepan, stirring constantly until blended. Add the fish and simmer, covered, until the fish is just opaque, about 5 minutes. Stir in the chopped thyme.

5

Place 4 garlic toasts in the bottom of each of 4 soup bowls. Pour about 1 1⁄4 cups of the soup over the toasts in each bowl. Yields 1 bowl per serving.