Make pasta dough, if making your own, either by mixing the ingredients by hand or mix them together in a mixer/food processor until they come together. Knead briefly then cover and let rest while you mix the filling.
For filling, break the lobster meat up into very small pieces. Put in a bowl with the ricotta and lemon zest and mix well so everything is evenly distributed.
Roll the pasta dough out around ⅛th of the quantity at a time, keeping the rest covered. Flour the piece of dough you are rolling every few rolls to keep it well-floured so it doesn't stick. If using a pasta machine I tend to roll to around "5" setting, but you can also roll by hand. You want it very thin, almost see-through, but still holding together.
If using a mould, put the dough over mould and put around a teaspoon of filling in each space. If just on a floured surface, put the piles of filling around 1 inch apart.
Dab water between the piles of filling/along where the mould edges are. Put another layer of pasta over the top and seal in the filling, trying to avoid air in filling.
Cut the ravioli (roll over the mould with a rolling pin then invert the mould if using a ravioli mould), set aside on floured baking sheet and repeat with rest of dough and filling.
Set water to boil in a wide pot to cook the ravioli, and separately melt the butter in a skillet for the sauce. Once it has melted, keep cooking until it starts to brown and go nutty smelling. Thinly slice the sage and add to the pan, cook a minute more. Set aside.
Once ravioli are formed, put them into the pot of boiling water a few at a time and cook for a couple minutes. You will need to keep the heat relatively high to keep the water boiling uncovered. The ravioli will float up to the top when ready. Give them just a minute more once they float up then remove with a slotted spoon and put into serving dish. Drizzle over browned butter. Repeat with rest.