Slice the steak into thin strips. 

Prepare the marinade: mixing brown sugar, garlic, chile powder, smoked paprika, cumin, salt and pepper together in a bowl.  

Pour in 1/4 cup of olive oil and lime juice from 2 limes, whisking together.

Pour marinade into a zip top baggie with the sliced steak, squeezing out excess air.

Seal and turn over several times until steak is well coated in the marinade.

Refrigerate steak at least 4 hours and up to 24 hours if possible.

Prepare a grill fire to about 400° using pecan or oak for smoke flavor.

Slice the peppers and onions. 

Place a griddle or a cast iron skillet onto the grill. Close the grill for about 2 - 3 to heat the griddle.

Coat the cooking surface with about 2 tablespoons of olive oil and add peppers and onions. 

Cook, stirring often until vegetables start to caramelize.

Remove peppers and onions to a pan and set aside.

Add remaining olive oil to the griddle. 

Place marinated steak onto the griddle and cook, stirring frequently.

When steak starts to brown, squeeze juice of one lime over steak. Continue to cook about 2 minutes.

Add peppers and onions back to the griddle. Mix with steak, cooking about 2 more minutes.

Carefully remove griddle from the grill. 

Garnish with cilantro and lime slices.

Serve steak and onions with flour tortillas, salsa, cheese and sour cream.