Crumble tempeh into pea-sized pieces. Heat oil in a large nonstick skillet over medium-high. Add tempeh; cook, undisturbed, until bottom of tempeh is golden brown, about 5 minutes. Add bell pepper and finely chopped onion; reduce heat to medium, and cook, stirring often, until bell pepper is tender-crisp and onion is translucent, about 4 minutes. Add cumin, chile powder, and garlic powder; cook, stirring often, until spices bloom and become fragrant, about 1 minute. Add soy sauce, ketchup, and remaining 2 teaspoons lime juice, 1/2 teaspoon salt, and 1/3 cup water; cook, stirring constantly, until tempeh absorbs soy sauce mixture, about 2 minutes.