Step 1

Position a rack in the middle of the oven and preheat to 375 degrees.

Step 2

Pour 2 inches of water into a large saucepan over medium-high heat. Set a steamer basket inside, and transfer the cauliflower to the basket. When the water begins to boil, reduce the heat to medium, cover and steam the cauliflower until barely tender but not mushy, about 5 minutes. Transfer the florets to a cutting board, cut into smaller pieces and transfer to a large bowl.

Step 3

While the cauliflower is steaming, heat a large cast-iron skillet over medium-high heat until smoking. Add the chiles and cook, stirring once or twice, until pliable, 30 seconds to 1 minute. Transfer to a small bowl, cover with the boiling water and let soak until soft, 5 to 10 minutes. Return the skillet to medium-high heat.

Step 4

While the chiles soak, add the onion and garlic to the empty dry skillet and cook, turning occasionally, until lightly charred all over, 2 to 3 minutes. Peel the garlic, discarding the skins, and transfer the cloves and the onion pieces to a blender. Add the chiles and all their soaking liquid, plus the tomatoes, vinegar, oregano, salt and pepper, and blend until smooth.

Step 5

In a medium saucepan over medium heat, heat the oil until shimmering. Using a splatter guard if needed, add the pureed chile sauce and cook, stirring occasionally, until it slightly thickens and darkens, about 10 minutes. Taste, and season with more salt and pepper as needed.

Step 6

Add the crumbled feta to the bowl with the cauliflower and toss to combine.

Step 7

Brush the tortillas lightly on both sides with oil and microwave them on HIGH for about 30 seconds, until hot. Let cool slightly.

Step 8

Spread 1 cup of the sauce on the bottom of an 8-inch-square casserole dish.

Step 9

Working with one tortilla at a time, put a generous 2 tablespoons of the cauliflower mixture along the bottom third of the tortilla and roll the tortilla around the filling. Set the roll, seam side down, on the sauce in the dish, and repeat with the remaining tortillas and filling.

Step 10

Spoon the rest of the sauce over the enchiladas. Top with dollops of the crema. If you have a little extra cauliflower filling, sprinkle it on the sauce. Evenly sprinkle the Monterey Jack on top.

Step 11

Bake for about 15 minutes, or until the cheese is melted. Serve hot.