Put the tomatoes in a bowl and sprinkle with 1 teaspoon salt; let sit 30 minutes.
Meanwhile, whisk the lime juice, mustard, honey, jalapeno, thyme, 1/2 teaspoon salt, and pepper to taste in a large bowl. Gradually pour in the olive oil, whisking constantly until emulsified.
When ready to serve, halve the avocados, remove the pits, peel and thinly slice. Add to the bowl with the dressing, then add the lettuce and tomatoes. Gently toss to coat. Season with salt and pepper.
Photograph by Con Poulos
Courtesy of Food Network Magazine