Preheat the oven to 425°F. Combine all cauliflower ingredients from the olive oil through the salt. If you desire more spice, add an additional tablespoon of adobo sauce. Whisk to combine, then pour over the cauliflower florets. Stir to evenly coat.
Add the coated cauliflower florets to a baking sheet, then roast for 35 minutes, tossing halfway through. They should be golden and crispy when done.
While the cauliflower is roasting, combine all slaw ingredients in a mixing bowl. Adjust seasoning as needed.
To prepare the tangy garlic sauce, add all ingredients except the water to a bowl. You can use a zester to mince the garlic. Stir to combine, then slowly pour in water until you reach the desired consistency. The sauce should be able to be drizzled similarly to a salad dressing.
Warm your tortillas in the oven or over a burner, then add them to a serving plate. To assemble the tacos, place a dollop of tangy garlic sauce on each tortilla. Add a handful of the slaw, roasted cauliflower, avocado slices, and additional garlic sauce drizzled on top.