In the first skillet, add 2 tablespoons (30 ml) of olive oil over medium heat. When the oil is hot and shimmery, add the sliced onions. Lightly sprinkle with salt and saute until the onions are deeply caramelized, about 40 minutes, taking care not to let them burn. Using a slotted spoon, transfer the onions to a paper towel lined plate to absorb any excess oil.
Meanwhile, add 1/4 cup (60 ml) olive oil to the other skillet over low-medium heat. When the oil is hot and shimmery, add the diced onion. Lightly sprinkle with salt and saute until tender and translucent, about 7 minutes.
Add the garlic and cumin and stir together until fragrant, about 30 seconds.
Lower the heat to a simmer and add the cooked rice and lentils. Season lightly with salt and pepper and gently mix to combine. Use a fork to lift and fluff until heated through, 5-6 minutes.
To serve, add the crispy onions on top of the rice and lentils, drizzle with extra virgin olive oil and fresh parsley, and bring the skillet to the table family-style. Have Greek yogurt or hummus at the table to serve alongside.