1. Finely chop the onion.
2. Heat the oil in your pressure cooker over medium-high heat until very hot. Add the onion and stir it around until it is coated with the oil. Reduce the heat to low and sauté gently, stirring every now and then, until softened, 5 to 10 minutes.
3. Meanwhile peel and slice the carrots or parsnips ½ inch thick. Finely shred the cabbage. Scrub and quarter the potatoes. Add these vegetables to the pot along with the stewed tomatoes and water. Bring the liquid to a simmer over high heat. Peel the garlic but leave it whole. Add the garlic, 1 teaspoon salt and sugar (omit the sugar if you’re using parsnips).
4. Remove as much of the skin and fat from the chicken as possible and add the pieces to the pot. Cover the pressure cooker, lock the lid, and bring to full pressure over medium-high heat. Cook at full pressure for 12 minutes.
5. Meanwhile mince or, easier yet, finely snip the dill, if using, with scissors.
6. Cool the pressure cooker under cold running water until the pressure is normal. Release the pressure and unlock the cooker, averting your face as you do so to prevent a steam burn. Add the lemon juice and dill to the pot, stir, and season to taste with salt and pepper.
Substitute an additional 12 pound carrots or parsnips for the cabbage.