Using a mandolin or sharp chef’s knife slice radishes into paper thin rounds and cabbage into thin strips. Transfer to a medium bowl and mix in the scallions, 1 Tbsp. olive oil, lime juice and 1/4 tsp. of salt. Massage and squeeze the cabbage with your hands to help it release its liquid and begin wilting. Set aside.Pat the cod dry with paper towels; season with salt, pepper and a pinch of cumin on both sides. In a large pan, heat 3 Tbsp. olive oil on medium-high heat until hot. Add the cod and cook until golden brown and cooked through, about 3 or 4 minutes per side. Transfer cod to a plate and add diced tomato to the hot pan. Stirring constantly, cook the tomato for about 3 minutes, until it begins to break down. Season with salt & pepper. Divide the slaw between two plates, top with cod, tomato and cilantro leaves.