Trim any excess fat from the ribeye and slice into thin strips against the grain.
In a small bowl, combine the chili powder, cumin, smoked paprika, sea salt, and black pepper.
Toss the steak strips in the spice blend until evenly coated.
Heat the avocado oil in a cast-iron skillet over medium-high heat until shimmering.
Add the steak to the skillet in a single layer and sear for 2-3 minutes per side until a dark crust forms.
Remove the steak from the pan and let it rest; in the same pan, quickly warm the black beans with a splash of water.
Warm the corn tortillas over an open flame or in a dry pan until soft and slightly charred.
In a small bowl, toss the shredded cabbage with lime juice and cilantro to create a quick slaw.
Assemble the tacos by layering the black beans, ribeye strips, and cabbage slaw into the tortillas.
Top with salsa verde and serve immediately.