Bring some water to boil, add some salt and cook spaghetti according to instruction on the package. Drain and reserve a cup of pasta water
In a saucepan, warm up the olive oil and add in the lemon slices. let the lemon slices cook on low heat until it shows signs of browning/caramelization
Add in the thyme into the saucepan with the olive oil.
Add in cooked spaghetti into the pan with about 2 tablespoons of pasta water. Swirl gently to allow the flavored oil coat the spaghetti
If using olives or cooked protein and vegetables, add it into the pan and mix for about a minute. Serve the lemony spaghetti with thyme.