In a large bowl, mash or roughly chop the roasted chickpeas, leaving visible chunks and a few whole beans for texture. Be careful not to over-mash the chickpeas to avoid them becoming too creamy. Add in mayonnaise, dill, granulated onion, granulated garlic, salt, pepper, and minced shallots (if using). Taste the mixture, and add in remaining mayo as desired for additional creaminess and flavor.