While the potatoes are roasting, heat the olive oil in a pan, on medium heat, and, when hot, add the tomato paste, cumin, turmeric and smoked paprika and fry for 2 minutes. Add the sliced onion, salt and black pepper and cook on medium heat for 6 minutes . Add the minced garlic and fry for 2 minutes, stirring to prevent burning. Add the red bell pepper, soy sauce, can of chopped tomatoes, thyme, rosemary, and canned or cooked lentils. Simmer for 10 minutes.