Place the sliced flat iron steak in a bowl and sprinkle with smoked paprika, cumin, salt, and pepper. Toss well to evenly coat all the pieces, letting the spices settle into the meat for about 5 minutes.
Heat a skillet over high heat and add a tablespoon of olive oil. Once shimmering and hot, carefully lay the steak strips into the pan in a single layer.
Sear the steak for 2-3 minutes without stirring, until the edges develop a deep golden-brown crust and the aroma of smoky spices fills the air.
Use tongs to flip the steak strips and cook for another 2 minutes, ensuring they are cooked through but still tender. Remove from the pan and set aside.
Add the remaining tablespoon of olive oil to the same skillet. Toss in the sliced onions and peppers, stirring frequently, until they soften and start to char slightly, about 5 minutes.
Return the cooked steak strips to the skillet with the vegetables and toss everything together for 1-2 minutes, allowing the flavors to meld and the ingredients to heat through.
Chop fresh cilantro and sprinkle over the hot skillet mixture. Squeeze fresh lime juice on top to add brightness and balance the smoky flavors. Serve immediately with lime wedges on the side.