If you're using an Instant Pot, set it to Sauté, spray with some low calorie cooking spray and cook the onions, spring onions, garlic and bacon until they start to brown slightly.
If you're not using an Instant Pot, sauté the onions, spring onions, garlic and bacon in a pan.
Bring to the boil, then turn the Instant Pot to Slow Cook on medium for 3 hours.
If you're not using an Instant Pot, transfer the contents of the pan to the slow cooker and cook for 3 hours.