Preheat the oven to 425 °F (218 °C). Place the cauliflower florets on a baking sheet and spray with cooking spray. Roast for 25-30 minutes or until slightly charred and tender. While the cauliflower is cooking, make the tinga sauce and slaw.
Slaw:
Mix together the ingredients in a large mixing bowl, refrigerate until ready to use.
Tinga Sauce:
Place a large skillet over medium heat. Add the oil to the pot along with the onion and garlic clove. Cook 4-5 minutes until soft but not browned.
Add the tomatoes, chipotle chilies, salt, and oregano to the pot and bring to a low simmer. Cover and cook for 10 minutes stirring occasionally until the tomatoes are very soft. Use an immersion blender to blend the sauce or transfer to a blender and blend until smooth then transfer back to the skillet.
Add the roasted cauliflower to the sauce and stir to combine. Cook an additional 2-3 minutes.
To Serve:
Fill each tortilla with slaw, cauliflower tinga, and top with radishes, extra jalapeno, and cilantro. Serve immediately.