Note: if desired, you can marinate the peppers and onions 24 hours ahead of time and store in the fridge.
Preheat the oven to 425 degrees F. Prep a baking sheet (line with foil or spray with nonstick spray!) to use for the recipe. You can also use two baking sheets for this recipe, to ensure that the vegetables roast properly and don’t steam instead. For this particular recipe, I don’t mind if mine are a bit softer.
In a bowl, whisk together the olive oil, lime juice, zest, honey, cumin, chili powder, paprika, salt, pepper and garlic.
I place the cauliflower florets in a bowl and the peppers and onions on the sheet pan. You can toss everything together and roast but I prefer to keep them separate on the pan. I drizzle half of the marinade on the cauliflower florets and half on the peppers and onions. Toss everything well and make sure every bit is coated.
Keep the onions and peppers on one side while the cauliflower is on the other side.
Roast for 15 to 20 minutes, then toss and roast for another 10 more, or until soft and slightly charred. Remove the baking sheet and place the black beans on it (anywhere works). Return the pan to the oven for 5 to 10 minutes.
Once the vegetables are done, assemble your fajitas! Start with cauliflower and some avocado slices, add the peppers and onions on top. Spritz with lime, sprinkle with cotija cheese and top with sour cream and fresh cilantro if you wish.