Halve the avocados and remove the pits. Dice the avocado inside the skin and scoop into a medium bowl. Add the lemon juice and mash with a fork until you get the desired consistency.
Add the red onion, roasted peppers, olives, tomatoes, garlic and most of the feta, parsley and dill, reserving some for garnish. Add the salt and cumin and mix together until well combined. Taste and adjust the seasoning if needed.
Transfer to a serving a bowl and sprinkle over the remaining feta, parsley and dill. Serve with the sliced cucumbers and tortilla chips.