Fry onion, capsicum and bacon in frypan until onion is soft. Add mushrooms, carrot, zucchini, asparagus and spinach. Stir, cook until spinach slightly wilts. Strain this mixture of any excess liquid.
In a large bowl add the eggs, milk, mustard, salt and pepper, mix well to combine.
Add half the cheese to egg mixture along with the peas and corn. Mix well.
Add the strained veggie mixture to the bowl and mix well to combine.
Line slow cooker bowl with baking paper, leave a generous over hang of paper so you can easily lift out quiche once cooked.
Place potato gems in a single layer across bottom of bowl and about 3 gems high around sides of bowl.
Gently pour in the egg and veggie mixture into the centre of bowl over the potato gems.
Arrange sliced tomatoes on top and sprinkle remaining cheese over the top.
Cover with a tea towel under the lid and cook on high for 2 to 3 hours.
Centre should feel firm when you insert a knife into the middle and the outer potato gems should brown.
Used a 6L Modern Living oval slow cooker.
Could use any vegetables that you like.