Slice each tomato ¾ of the way crosswise about ½ inch from the top of the tomato,leaving the top attached. Scoop out the tomato seeds and meat from the inside and discard. Set aside.

Bring a medium pot full of water to a boil. Peel the onions and cut off the onion root.  Slice each onion lengthwise halfway through the center of the onion. Place the onions into the boiling water and cook for about 8 to 10 minutes until the onion layers are soft and start to seperate. Using a slotted spoon, gently remove the onions from the boiling water and let them cool until they can be handled easily. Keep the pot of water boiling on high heat. Gently separate each onion layer without tearing. Place the separated onions layer on the aside. 

Place the rinsed and drained rice into the pot of boiling water and cook it for about 5 minutes. Drain and discard the water.

Place all the ingredients for the filling into a large bowl and mix to combine well. 

Stuff the tomatoes: Using your hands, place about 1 heaping tablespoon of the filling into the cavity of each tomato. 

Stuff the onions: Lay out one onion layer. Place 1 heaping tablespoon of the mixture on the left side of the inside of the onion layer. Starting with the edge closest to the filling roll the onion layer up into a sealed torpedo shape. Continue with the remaining onion layers. 

Place the oil into the bottom of a large Dutch oven or saucepan and heat over medium-low. Add 2 teaspoons of turmeric, 2 teaspoons of granulated sugar, and ½  teaspoon of salt into the oil and stir. Gently place all the tomatoes along the outer edge of the pan, with their top side down in one layer. Gently place the onions into the middle of the pan with their seam side down in the same layer as the tomatoes. Cover the pan with a lid and cook for 20 minutes. Uncover and sprinkle the remaining ½ teaspoon of salt over the tomatoes and onions. Cover and continue cooking for 15 to 25 more minutes until the filling is cooked through and the tomatoes and onions are tender.

Once ready, uncover the pan and sprinkle the remaining lemon juice over the vegetables. Transfer to a serving platter and serve hot.