Heat oil in a large nonstick skillet over medium-high heat. Add peppers and cook, stirring occasionally, until bright green and just starting to soften, about 3 minutes. Stir
in tomatoes, cumin and salt; cook, stirring often, until the tomatoes start to break down,
2 to 3 minutes. Crumble polenta slices into the pan and cook, stirring occasionally, until heated through, 1 to 2 minutes. Stir in scallions, cheese, cilantro and lime juice. Serve the scramble topped with diced avocado and toasted pepitas.