1. Prepare the Onions: Begin by peeling the yellow onions. Cut each onion in half lengthwise, then slice them into thin, even half-moon shapes. Aim for slices about 1/4-inch thick so they cook evenly.

2. Saute the Onions: Heat the olive oil in a large skillet or pot over medium heat. Once shimmering, add the sliced onions. Cook, stirring occasionally, for about 5-7 minutes until the onions begin to soften and turn translucent. They should not brown significantly at this stage.

3. Add Liquids and Seasoning: Pour in the vegetable broth (or water) and fresh lemon juice. Stir in the dried oregano, sea salt, and black pepper. Bring the mixture to a gentle simmer.

4. Simmer and Soften: Reduce the heat to low, cover the skillet, and let the onions simmer for 10-12 minutes. The onions should become very tender and almost translucent. Stir occasionally to prevent sticking and ensure even cooking.

5. Stir in Fresh Herbs: Once the onions are tender and most of the liquid has been absorbed or evaporated, remove the skillet from the heat. Stir in the fresh chopped parsley and chives. The residual heat will gently warm the herbs, releasing their fragrance.

6. Taste and Adjust: Taste the onions and adjust the seasoning as needed. You might want a little more salt, pepper, or a squeeze of extra lemon juice to brighten the flavors.

7. Serve Immediately: Transfer the warm onion boil to a serving dish and serve hot. The onions will be soft, flavorful, and ready to enjoy.