In a medium saucepan, heat 1 tablespoon of the olive oil with the garlic cloves and cook over moderate heat until the garlic is lightly browned in spots, about 2 minutes. Add the Israeli couscous and cook, stirring, until lightly browned, about 2 minutes. Add the water, season with salt and bring to a boil. Cover and cook over low heat until the couscous is tender and the water is absorbed, about 10 minutes.
Pick out the garlic cloves from the couscous and mash them to a paste. Transfer the garlic paste to a large bowl and whisk in the lemon juice and the remaining 1/4 cup plus 2 tablespoons of olive oil. Season with salt and pepper and stir in the couscous. Refrigerate for 10 minutes, just until no longer warm.
Add the parsley, lovage, mint, chives, jalapeño, tomatoes and cucumber to the couscous and toss well. Season with salt and pepper and serve.