Now for the bouilli sauce or the base: 

5-6 Tbsp of flour in 1 1/2 cup of milk and about 1/3 cup of sugar plus zest of 3-4 bright oranges, all boiled to a very thick sauce under constant stirring. 

When slightly (1-2 min.) cooler add 8 egg yolks one by one violently whipping until incorporated. 

Now add 4-5 Tbsp butter in small dots on top, and at this point you can leave the bouilli for several hours, however , before adding the whites, you must heat up the base until it is "finger warm". 

Before adding the whites, add to the slightly warm bouilli 6-8Tbsp orange liqueur or rum.

Beat the 8+2 extra egg whites until foamy, add a pinch or two of salt and continue until soft peaks are formed. 

Ever so slowly sprinkle 1/3 cup of sugar until the peaks are firm. Stir this "meringue" into the bouilli little by little, handling as little as possible. The first part you don't have to be so careful with, but the later parts should be incorporated by getting the sauce over the whites from the bottom breaking the whites at the same time, not hard to do but it takes a bit of practice, like mixing an angel food cake!

Put the soufflé in the container in the oven at 375° F, preheated of course, for 40-45 min., it will rise and " break " on top. Take off the paper carefully and serve IMMEDIATELY, it will NOT wait for you, and as soon as you start serving it will collapse, but don't panic, that's the way of soufflé's.

Serve this with orange sauce:

About two cups of orange juice, juice of one or two lemons, a good dollop of sugar, al gusto, 4 Tbsp of maizena (corn cornstarch), stirring over medium heat until thick. If too thick (and it will be) dilute with rum or orange liqueur until thick, runny, serve warm with the soufflé