Prepare farro according to package instructions in water or chicken stock.
Coat the bottom of a Dutch oven or other heavy-bottomed pan generously with olive oil, and set it on medium heat. Add the onions and a pinch of salt and sauté for about 10 minutes until softened, then lower the heat to lightly caramelize, about 20mins more.
Add the carrots to the onions, season with salt, and cook until tender, another 15 minutes.
Add the prepared farro to the pot, dressing with additional olive oil and seasoning with salt and pepper. Add a squeeze of lemon juice to taste , and sprinkle with crumbled ricotta salata.