Wash and dry all produce. Preheat the oven to 400 degrees. Core, seed and thinly slice the bell pepper. Thinly slice the scallions, keeping the greens and whites and separate. Finely chop the cilantro. Cut the lime into wedges. Thinly slice the radishes.

Halve and pit the avocado, then scoop the flesh into a small bowl. Add 1 Tablespoon scallion greens, half the cilantro, and a squeeze of lime. Mash with a fork until smooth. Season to taste with salt and pepper.

Heat a drizzle of oil in a large pan over medium-high heat. Add the bell peppers and cook, tossing for 5-6 minutes, until softened and slightly charred. Add the scallion whites and cook for another minute. Season with salt and pepper.

Warm the tortillas: While the peppers cook, wrap the tortillas in foil and place in the oven to warm. Alternatively, heat a burner to medium-low and place each tortilla over the flame for about 15 seconds per side, until lightly charred in spots. Set the warmed tortillas aside under a kitchen towel or wrapped in foil.

Add the ground beef and cumin to the pan with the veggies and cook, breaking up the meat into pieces, until browned and cooked through. Season with salt and pepper. Finish with a squeeze of lime juice.

Assemble the smoky beef tacos: Spread each tortilla with guacamole, then top with the beef mixture, radish slices, the remaining cilantro, and scallion greens. Serve with a wedge of lime and sour cream for dolloping on top. Enjoy!