1. Preheat oven to 425F.
2. Toss cauliflower pieces, garlic, and chickpeas with olive oil and salt. Spread on to a large baking sheet (don’t crowd the vegetables to ensure you get roasted bits). Roast for 25-30 minutes, watching to make sure the chickpeas don’t get hard.
3. While the cauliflower and chickpeas are roasting, mix together the mayo and the dill in a large bowl and set aside.
4. When done, remove the cauliflower and chickpea mixture from the oven and allow to cool for 5 -10 minutes. When cooled enough to handle, add to the dill and mayo mixture, and stir until well combined. Refrigerate until ready to serve. Can be made up to 2 days before serving.
5. To assemble the sandwich, spread the salad on the bread and top with sliced cucumbers. Enjoy.