My grandfather taught me the secret to the ultimate savory summer lunch. It only takes 3 items but tastes like pure childhood comfort on a hot day.

This 3-ingredient southern tomato sandwich is the kind of simple, savory summer lunch my grandfather swore by. It’s nothing more than soft white sandwich bread, thick slices of sun-warm tomatoes, and a generous swipe of mayonnaise, but together they taste like pure childhood comfort on a hot day. Versions of this sandwich have been a staple across the American South for generations, especially when backyard gardens and farm stands are overflowing with ripe tomatoes. It’s the kind of recipe that reminds you how little you need when your ingredients are at their peak.

Serve this sandwich on a plain paper plate, just as you might have eaten it on a back porch or at a picnic table, with a handful of potato chips or crisp cucumber slices on the side. A cold glass of iced tea or lemonade keeps the meal light and refreshing, and a few extra tomato slices with a pinch of salt make a nice little bonus. This is meant to be eaten immediately, while the bread is still soft, the mayonnaise is creamy, and the tomato juices are just starting to soak in.

Servings: 1

2 slices soft white sandwich bread

Lay the 2 slices of soft white sandwich bread on a clean surface, paper plate, or cutting board. Do not toast the bread; the classic southern version relies on the tender, squishy texture of plain white bread.

Spread a thick, even layer of full-fat mayonnaise over one side of each bread slice, going all the way to the edges so every bite is creamy. The mayonnaise is acting as both seasoning and barrier to keep the bread from getting soggy too quickly.

Slice the ripe red heirloom tomato into thick, generous rounds, about 1/4 to 1/2 inch each. Pat the slices very lightly with a paper towel only if they are dripping excessively, but leave them juicy—that’s part of the sandwich’s character.

Arrange the tomato slices in a single, full layer over one piece of the mayonnaise-coated bread, slightly overlapping so there are no gaps. The tomatoes should form a thick, substantial layer that you can see clearly from the side of the sandwich.

Lightly press the second slice of bread, mayonnaise side down, over the tomatoes to form a sandwich. Gently press with the palm of your hand so the mayonnaise and tomato juices just begin to mingle and the filling squishes slightly to the edges.

Cut the sandwich in half on the diagonal if you like, keeping it on the paper plate for that nostalgic, casual feel. Serve and eat immediately while the bread is soft, the tomatoes are juicy, and the mayonnaise is still cool and creamy.

For a subtle flavor shift while keeping the 3-ingredient spirit, you can use different styles of mayonnaise, such as a tangier Southern-style mayo or one made with olive oil. If your tomatoes are less than peak-season sweet, a very light sprinkle of salt can help, but try to rely on truly ripe, in-season tomatoes whenever possible—they are the heart of this sandwich. You can also experiment with different heirloom varieties: deep red beefsteak-style tomatoes give you those big, juicy slices you see in classic summer sandwiches, while striped or darker heirlooms add a slightly more complex flavor. If you need to make the sandwich ahead by a few minutes, spread the mayonnaise generously and keep the assembled sandwich in a cool spot; the mayo helps slow down sogginess, but this is still best eaten within 15 to 20 minutes. For food safety, keep mayonnaise and sliced tomatoes refrigerated until just before assembling, especially on very hot days or if you’ll be eating outdoors. Avoid leaving the finished sandwich out at room temperature for more than 1 to 2 hours, and discard any leftovers that have been sitting in direct sun or high heat. Always rinse tomatoes under cool running water and dry them before slicing to remove any surface dirt, and use a clean cutting board and knife to minimize cross-contamination.