When I was growing up, my typical lunch on a cold or rainy Saturday was grilled cheese sandwiches with tomato soup. Now, instead of serving the sandwiches whole, I cut them into croutons, mound them on a big platter, and let people spoon as many croutons into their soup as they like. If you're serving this to kids, you may want to halve the amount of garlic and leave out the jalapeño.
1. For the Soup: Heat the oil in a large saucepan over medium heat; add the onion, garlic, jalapeño, salt, and pepper and cook, stirring, until translucent, about 10 minutes. Add the tomatoes and stock and bring to a simmer. Simmer until the tomatoes are soft, 15 to 20 minutes. Whisk in the sour cream and the lime juice and turn off the heat. Blend the soup until smooth with an immersion blender or a regular blender (if using a regular blender, wait for the soup to cool a bit, then hold the blender lid on with a kitchen towel while you puree). Return the soup to the heat on low; don't let the soup boil or it will curdle.
2. For the Croutons: Heat a large skillet over medium-high heat. Butter 2 of the bread slices on one side and place 1 slice in the pan, buttered side down. Add enough slices of cheese to cover the bread evenly, then top with the second slice of bread, buttered side up. Brown until golden, 2 to 3 minutes, then flip over to brown the other side. Remove the sandwich from the pan and let it cool. Repeat with the remaining 2 bread slices and the cheese. Cut the cheese sandwiches into quarters and cut each quarter into quarters again to make cubes 1 to 2 inches wide. Pile all the croutons onto a serving platter.
3. 2 tablespoons unsalted butter, softened
4. 4 slices white bread or potato bread
5. 4 ounces sharp white cheddar, cut into slices
6. Cilantro Croutons: Sprinkle a few whole cilantro leaves (no stems) on top of the cheese before you cover it with the second slice of bread. When you cut the croutons, you'll see a subtle ribbon of green running through the center.
7. Ladle the soup into serving bowls and garnish each bowl with a dollop of sour cream and sprinkle with chopped cilantro. Set the platter of croutons where everyone can reach.