4 tablespoons extra-virgin olive oil, divided
2 tablespoons fresh lemon juice
2 large garlic cloves, minced, divided
1/2 teaspoon finely grated lemon peel
1 1/3 cups Israeli couscous (6 to 7 ounces)
1 3/4 cups (or more) vegetable broth
14 ounces slender asparagus spears, trimmed, cut diagonally into 3/4-inch pieces (about 2 1/2 cups)
8 ounces sugar snap peas, trimmed, cut diagonally into 1/2-inch pieces (about 2 1/2 cups)
1 cup shelled fresh green peas or frozen, thawed
1/3 cup chopped fresh chives
1/2 cup finely grated Parmesan cheese