Serves 4; can be multiplied.
1 medium purple eggplant, or 2 thin Japanese eggplant, cut into 3/4-inch dice
3 large (but not boat sized) summer squash: zucchini, yellow squash, patty pan, or a mix, diced
1 large onion, cut into 3/4-inch dice
1 red bell pepper, cut into 3/4-inch dice
2-3 Tbsp extra virgin olive oil
1-2 ripe tomatoes, cut into 3/4-inch dice, or a large handful of cherry tomatoes
3-4 Tbsp shredded fresh basil leaves
For the vinaigrette:
2 Tbsp balsamic vinegar
1 tsp mild agave nectar
1-1/2 tsp Dijon mustard
1/4 cup olive oil (not fruity)
Pinch each of kosher salt and fresh black pepper
Preheat the oven to 400°F. Line a rimmed baking sheet with aluminum foil.
Spread the eggplant, squash, onion and bell pepper on the baking sheet. Sprinkle lightly with kosher salt and fresh black pepper, and toss with extra virgin olive oil. Spread in a single layer. Roast for 45 minutes, turning the vegetables once.
While the vegetables are cooking, place all ingredients for the vinaigrette in a jar with a tight-fitting lid, and shake the jar vigorously until the dressing has emulsified (thickened).
When the vegetables are done, transfer them to a large mixing bowl. Add the tomatoes and fresh basil, and toss with as much of the vinaigrette as you need (but not too much).
Serve hot, at room temperature, or chilled.