Pre-heat oven to 350 degrees. Heat 3 tbsp olive oil in a saute pan over med-high heat, and fry onion and garlic until onion begins to become translucent, about 5 minutes. Add bell pepper and continue to saute for another 5 minutes. Beat eggs and add to pan. Add basil, rosemary, salt and pepper and stir to combine. Lower heat to med-low and let sit for 10 minutes. transfer to oven and bake until cooked through and top has set, about 15 minutes.
Meanwhile in another saute pan over med-high flame, heat 1 cup olive oil. When oil just begins to smoke add sweet potatoes and fry, one layer at a time (don't overcrowd) until golden brown and crispy. Remove with a slotted spoon to a paper towel lined plate. Top frittata with the sweet potato crisps and serve hot.