In skillet, heat 2 tbsp of the oil over medium-high heat; sauté pine nuts until slightly darkened, about 2 minutes. Add onions and garlic; cook, stirring occasionally, until softened, about 3 minutes.
In large bowl, combine onion mixture, rice, tomatoes, parsley, mint, half of the lemon juice, the currants, salt, cinnamon, sugar, pepper and cloves; set aside.
Rinse grape leaves under cold running water. In large pot of boiling water, blanch, in 2 batches, for 3 minutes. Chill under cold running water; drain. Pat leaves dry; cut off stems.
Line shallow Dutch oven with any broken leaves or 5 whole leaves. Lay 1 grape leaf, shiny side down, on work surface; place rounded tablespoonful of the rice mixture on bottom third of leaf; fold over sides and roll up snugly but not as tightly as possible. Repeat with remaining grape leaves and rice mixture.
Place rolls, touching and seam side down, in Dutch oven. Pour 2 cups water and remaining olive oil and lemon juice over top; cover rolls with inverted heatproof plate. Cover with lid and bring to boil; reduce heat and simmer for 45 minutes. Uncover and cook until liquid is evaporated, about 5 minutes. Let cool for 30 minutes. (Make-ahead: Refrigerate, uncovered, in airtight container until cold. Cover and refrigerate for up to 3 days.)