Melt margarine in a pan and add onions. Saute over Medium-Low heat about 7 minutes until translucent. Add salt, several grinds of black pepper and stir in flour until it is all smooth and bubbly.
In the meantime, turn your crock pot on LOW. Add chicken stock, carrots and potatoes. When onion roux is ready, stir it in as well. Cover and cook on LOW 4-7 hours or until potatoes are tender. Make sure you check it periodically, especially after the 4 hour mark so your veggies don’t turn to mush. Stir, turn to WARM and add diced chicken and frozen peas.
Preheat oven to biscuit-cooking heat. If you are so inclined, spray the top edges of your slow cooker. Drop biscuits dough in like dumplings. Place crock in the oven without the lid and bake for 15-20 minutes (usually about five minutes longer than recommended for cooking biscuits on a baking sheet).
Remove from oven, allow to cool for at least ten minutes. Serve it up in bowls and enjoy!