You need a baking pan that can be tightly covered. You can use a larger butter cookies tin or two stardard size tins (double the sugar if you are using two tins). This custard is better made in the pressure cooker (but can be baked in the oven, also). Your baking pan should fit in your pressure cooker. If using two tins, they need to be cooked separately.
Place the whole eggs in a large mixing bowl, stir them softly, folding them until they are well mixed. Fold in one egg yolk at a time, slowly, again in a folding motion. Continue until all the eggs are mixed in. Add the condensed milk, one can at a time, and then each can of evaporated milk. Add the pinch of salt and the vanilla. Don't forget to mix everything in following the slow folding process.
Slowly pour the mixture into the prepared baking dish(s) or tins, straining it with a fine colander as you pour it, covering it tightly with aluminum foil. Pour one inch of water into the pressure cooker and carefully place the baking dish inside. Cover the pressure cooker and after it is fully pressurized count 25 minutes. Turn the heat off, retrieve the pressure cooker from the burner, and let it rest until the pressure is release and cooled down by itself. Do not force the pressure out by releasing the valve. The custard needs this additional time to cook well.
Place the custard, still covered, in the refrigerator. Let it cool overnight.