Preheat oven to 400 degrees and prepare a baking sheet with aluminum foil. Thoroughly rinse produce and pat dry. Cut roasted peppers into thin strips. Stem and mince cilantro. Zest and halve lemon. Peel, halve, and cut red onion into ½" dice.

Place naan flatbreads on prepared baking sheet and brush with 2 tsp. of oil. Toast in oven 8 minutes until beginning to brown and crisp. Remove from oven. When cool enough to handle, cut each flatbread into 6 wedges. Reserve baking sheet for cauliflower step.

Trim greens and leaves from base of cauliflower. Place cauliflower head upside down on cutting board. Cut a straight line down either end of the stem, reserving the two side pieces. Cut center section in half to make two 1½-inch thick "steaks." Drizzle with olive oil, half the curry powder and a pinch of salt and pepper. Melt butter in a medium pan over medium high heat. Add cauliflower steaks and caramelize on one side for 4 minutes, then flip and brown second side 3 minutes. Transfer steaks and butter to baking sheet and roast in oven 6-8 more minutes until tender.

Roughly chop ¾ cup the reserved cauliflower side pieces. Add cauliflower to medium pot with raisins, half of the red onion, lemon zest, juice from one lemon half, and 2 Tbsp. of water. Bring to a boil and reduce to simmer. Continue cooking until liquid is mostly gone and cauliflower is tender. Remove from heat and add roasted red pepper and half of the cilantro. Season with a pinch of salt and pepper.

In the medium pan used for searing steaks, combine sour cream, tomato sauce, remaining curry powder, and juice from remaining lemon half. Warm gently over medium-low heat, but do not boil. Season with a pinch of salt and pepper and set aside. For the cilantro oil, combine remaining cilantro in a small bowl with 2 Tbsp. of olive oil.

Divide naan wedges between two plates. Spoon some of the tikka masala sauce in front of it and rest the cauliflower steak in the sauce. Garnish with the relish and a drizzle of the cilantro oil.