Halve and pit the avocados; scoop the flesh into a bowl. Mash with the lime juice and salt until mostly smooth with a little texture.

Fold in the red onion, jalapeño, and cilantro.

Spread the guacamole in a serving bowl. Pipe the sour cream in concentric circles over the top, then drag a toothpick from the center outward through the circles to create a spider web.

Serve immediately with tortilla chips.