Preheat oven to 400 degrees. To a large bowl, add all the Szechuan Steak Marinade ingredients and whisk to combine.
Dry the skirt steak well and add to the bowl of marinade. With tongs, toss well to coat and set aside on your counter to marinate and begin coming to room temperature .
To grill steak, remove from marinade, (reserving the marinade). Toss okra, orange bell, tomatoes and salt to marinade, tossing well. It's ok that raw steak was in the marinade- the sauce will cook with the vegetables.
Preheat a grill pan over medium high-heat for 3 minutes while you pat off any excess marinade and try to get the steak as dry as you can. When pan is hot, add 1/2 of the avocado oil and steak in a single layer to sear, 3-4 minutes on the first side. Flip steak and cook on the second side, turning down heat if needed, another 3-4 minutes.
Add seared steak to a sheet pan and finish in the oven for 5-7 minutes for medium rare, depending on thickness. Let steak rest on a cutting board tented with foil for 10 minutes before slicing.
While steak is finishing cooking and resting, return grill pan to medium heat and add remaining oil and vegetables in the remaining marinade. Cook veggies 7-10 minutes until veggies are lightly browned and tender.
Slice steak and serve atop vegetables in the skillet. Garnish with sesame seeds and basil leaves. Serve with steamed white rice.