Preheat oven to 450 F. Set a 10 inch cast iron skillet over medium heat and add 2 Tbsp olive oil. Place chicken thighs on the skillet and cook on each side for 6 minutes, for a total of 12-15 minutes, or until lightly browned and completely cooked through. Using tongs, set chicken thighs on a large plate. Let cool for 15 minutes. You will shred this with two forks (or your hands) while the sauce comes together.
If using store bought simmer sauce, add the shredded chicken back to the skillet. Add the butter and fry the chicken. Depending on the taste of your simmer sauce, you can add more cream, salt, chili powder, to your chicken now before adding the sauce. Or just dump in the simmer sauce and ¼ cup water. Stir the sauce and the chicken over low heat, allowing the chicken to further shred and absorb the sauce. Taste for spice and salt. Jump to step 5!
If making the sauce, add the butter and sliced onions to the cast iron skillet over medium heat. Saute for 3 minutes or until the onions are softened. Add the garlic and ginger powder and fry together for another 3 minutes. Once fried and aromatic, add 1 Tbsp kashmiri chili powder, ½ Tbsp turmeric, 1 tsp garam masala, 1 tsp ground cumin, 1 tsp ground coriander, and 1 Tbsp kosher salt. Continue to stir and fry until the spices have meshed with the alliums and are fully browned, about 5 minutes.
Add the lemon juice, marinara sauce, and cream to the skillet. Stir for another 5 minutes until everything is cohesive, then add the shredded chicken thighs. Stir and taste for salt and spice. Continue cooking until the sauce has reduced slightly and the chicken has significantly absorbed and melted into the sauce, about 10 minutes.
Once the sauce has thickened to a gravy-like consistency, take it off the heat and add 1 cup of the pimento cheese. Stir until mostly combined. Dollop spoonfuls of the remaining ½ cup of pimento cheese on the top of the dip and do not mix. Place in the 450 F oven for 5-8 minutes, or until the cheese has fully melted.
Remove the dip from the oven and sprinkle with freshly chopped cilantro. Serve immediately with toasted naan or pita bread. Enjoy!