Place beans in a bowl (or bag) and Salt & Pepper and a drizzle of oil to help seasoning stick.
Turn on vent hood/ exhaust fan.Coat heavy duty skillet with 1 TBSP Avocado Oil and allow to heat on high for 3 minutes. (I used cast iron.) Cook, over high heat for 12 minutes; Attentively stirring to allow beans to char but not burn.
When beans are soft but still firm, turn off heat; salt lightly then, allow beans to cool.
Add cooled beans to bowl with tomatoes, onion and cilantro.
In small bowl create a vinaigrette by adding lime juice, garlic and mustard. Drizzle Olive Oil slowly while whisking mixture. Pour over green bean mixture and stir in feta.
Enjoy immediately or chill in fridge until ready.