Add the eggplant and cherry tomatoes to a large rimmed baking sheet. Drizzle with the olive oil and sprinkle with the salt and pepper. Toss to combine and spread in an even layer. Bake for about 25 to 30 minutes, stirring once halfway through, until the tomatoes have shriveled and the eggplant is tender. Remove from the oven and let cool slightly.
For the spread:
Add all the ingredients for the spread to the bowl of a food processor fitted with an S-blade. Process until smooth, scraping down the bowl as needed. Add a little water (a tablespoon or so at a time) to get the spread to your desired consistency.
Smear some of the chickpea spread on a piece of bread. Top with some of the roasted veggies, the basil and chopped walnuts. Serve immediately.