Rinse the split peas in a fine mesh strainer and set aside.
If you are cooking the split peas in a pan on the stovetop, put them in a bowl and cover with water to soak overnight.
Chop the onion into small pieces.
Chop the celery into small pieces.
Grate the carrot on the small holes of a box or handheld grater (you can alternatively chop into small pieces).
Chop the bacon into small pieces.
Sauté the bacon in the pressure cooker or a pot on the stove (med heat) until cooked and browning.
Remove the bacon pieces and drain all but 1-2tbsp of the bacon fat.
Sauté the onion in the bacon fat.
Add the garlic once the onions are translucent (roughly 3-4 minutes) and sauté for 1 minute.
Add 1tbsp olive oil.
Add the carrots and celery and sauté until softening and slightly brown.
I like to add the split peas at this point and give them a little toasting for a couple of minutes but you don’t have to.
Add the stock and the water and stir completely.
Taste the mixture (minus the peas because they are hard!) and add salt and pepper as needed (I use roughly another tbsp. of salt and ½tbsp of pepper.
At this point you want to bring the mixture to a boil
Once boiling, if you are using the pressure cooker, put the lid on and set to the low pressure setting.
Lower the heat to med-high.
Once the pressure is reached and the steam is coming at a steady stream, reduce the heat to med or slightly below.
Pressure cook for 15 mins then turn off the heat and depressureize the pot until the pressure indicator is down. Don’t try to open under pressure please!!!!
If you are cooking on the stovetop, reduce the heat to simmer once a boil is reached and cover the pot. Simmer on low for a couple of hours until the split peas become soft and mushy. If you like some texture to the split peas, simmer for less time.
Serve and garnish with some chopped chives if you like (or even thinly slices green onion).