Prepare and Season Cauliflower: Preheat your oven to 400°F (204°C). Spread the cauliflower florets across two large rimmed baking sheets in a single layer to ensure even roasting. Drizzle with avocado or coconut oil, or substitute with a splash of water for oil-free cooking. Sprinkle the cumin, chili powder, smoked paprika, and sea salt over the cauliflower. Toss thoroughly using your hands or a spatula to coat all pieces evenly with the spices and oil.
Roast Cauliflower to Golden Perfection: Place the baking sheets on the lower rack of the oven. Roast the cauliflower for 20 to 25 minutes, stirring halfway through, until the florets are tender and develop a lovely golden-brown caramelization.
Roast Almonds and Garlic for Sauce: While the cauliflower cooks, arrange raw almonds and unpeeled garlic cloves on a separate baking sheet. Place this sheet on the middle rack of the oven and roast for about 10 to 12 minutes. Check at 8 minutes to avoid over-toasting almonds; remove them once they are crackling and browned. Continue roasting the garlic until it’s soft and lightly golden. Set aside to cool slightly.
Blend the Chipotle Romesco Sauce: In a high-speed blender, combine the drained fire-roasted tomatoes, roasted almonds, peeled roasted garlic, fresh raw garlic cloves, olive oil (or water), lime juice, smoked paprika, cumin, salt, maple syrup, and chipotle peppers. Blend on high until completely smooth and creamy. Taste and adjust seasonings by adding more lime juice for brightness, extra chipotle for heat, or additional maple syrup to balance the spice.
Warm Tortillas and Assemble Tacos: Gently warm the corn tortillas by placing them directly on the oven racks in the still-warm oven for a few minutes or microwaving wrapped in a damp towel until flexible. Spread 1 to 2 tablespoons of the chipotle romesco sauce on each tortilla, then pile on a generous helping of roasted cauliflower.
Garnish and Serve: Top the tacos with optional garnishes like fresh lime juice, cilantro, shredded cabbage, pepitas, or avocado slices. Serve immediately for the best flavor and texture.