Fill a large pot with water and salt and bring to a rolling boil. Cook lentils at a boil until tender yet firm to the bite, 15 to 20 minutes. Reserve lentils and water in the pot.
Heat 2 tablespoons oil in a saucepan over medium heat. Add onions; cook and stir until crispy and lightly browned, about 7 minutes. Transfer onions to a bowl. Combine cilantro and garlic in the saucepan; add 1 tablespoon oil. Cook and stir until wilted, 1 to 2 minutes. Transfer to a separate bowl.
Heat the remaining oil minus 1 teaspoon in the same saucepan. Add pita bread; fry until browned, 2 to 3 minutes per side.
Stir lemon juice, vinegar, and remaining 1 teaspoon olive oil into the pot of lentils. Bring to a boil; add pasta and half of the garlic-cilantro mixture. Cook, stirring occasionally, until pasta is tender yet firm to the bite, about 8 minutes.
Spoon lentil-pasta mixture in a deep dish. Decorate with the pita bread, onions, and the remaining garlic-cilantro mixture.
