Make the garlic condiment: Combine the garlic and lemon juice in a small bowl. Stir to blend, then stir in the oil, sugar, and salt. Set aside for 30 minutes. (This will mellow the strong flavor of the raw garlic).

Make the tahini dressing: Pour the tahini into a medium bowl. Whisk in the lemon juice and garlic, followed by the ice water a couple of tablespoons at a time. Keep whisking until the mixture is creamy with a consistency similar to a smooth hummus; you may not use all of the water. Whisk in the salt and several twists of pepper and set aside.

Assemble the salad: Toss the cherry tomatoes and jalapeño in a medium bowl with the lemon juice, oil, and salt. Spread the tahini dressing around the rim of a serving dish as you would hummus, leaving a well in the center for the tomatoes. Pile the tomatoes and jalapeño into the well, then spoon the garlic condiment over them. Season with pepper and serve immediately, before the tomatoes become soupy.