Grease a 6cm deep x 20 cm (base) round spring form pan and line the base and sides with baking/parchment paper and place on a large baking tray.
Remove and discard stems from the the silver beet (kale) and roughly chop the leaves.
Heat a fry pan/skillet over high heat and cook silver beet in batches stirring for 2 minutes or until wilted (how many batches will depend on the size of your pan) and transfer to a colander over a large bowl and using the back of a large spoon press silver beet/kale to drain excess liquid and cool for 5 minutes.
Combine onion, ricotta, feta, lemon rind, eggs and 1 cup of cheddar (tasty) cheese in a large bowl and add silver beet and add seasoning of salt and pepper and stir to combine.
Place 1 tortilla in the base of the prepared spring form pan and spread one-third of silver beet mixture over tortilla and repeat layers twice with tortillas and silver beet mix and finish with a tortilla and sprinkle with remaining 1/2 cup of cheddar (tasty) cheese.
Bake, uncovered for 5 minutes or until golden and then stand in pan for 5 minutes before you remove from the pan and cut into wedges.