The homemade balsamic reduction is the key to this healthy grilled eggplant and summer squash salad. It's easy to make but watch the vinegar as it reduces; it can burn easily. If you have any left over, drizzle it on strawberries.
Place vinegar in a small saucepan; bring to a boil over high heat. Reduce heat to maintain a simmer; cook, stirring occasionally and watching carefully to prevent burning, until syrupy and reduced to about 2 Tbsp., 12 to 15 minutes. Transfer to a small bowl and let cool.
Meanwhile, preheat grill to medium-high.
Slice eggplant, yellow squash, and zucchini diagonally into ¼-inch slices. Toss with 7 Tbsp. oil, salt, and pepper in a large bowl.
Grill the vegetables until tender and grill-marked, 2 to 5 minutes per side. Arrange on a platter.
Drizzle the vegetables with the remaining 1 Tbsp. oil and the reserved balsamic syrup. Top with olives and basil.
To make ahead: Cover balsamic drizzle (Step 1) and hold at room temperature for up to 1 day. Refrigerate vegetables for up to 1 day.
161 calories;14 g fat(2 g sat); 2 g fiber; 7 g carbohydrates; 1 g protein; 25 mcg folate; 0 mg cholesterol; 5 g sugars; 0 g added sugars; 149 IU vitamin A; 12 mg vitamin C; 19 mg calcium; 1 mg iron; 126 mg sodium; 267 mg potassium