Sorry for not being of help about Milan, but I can suggest you two
restaurants in Stresa I triesd last June:
Osteria agli Amici - I tried the pizza only, but it's restaurant too in a
nice setting, upper part of the town, outdoor dining under a shadowed patio.
The price is standard to moderate.
La Botte - just facing the pier there's a narrow street going into centre
and there you find this one-room pub-like restaurant. Mixed decor but a lot
of specialties, including local cuisine, pizza and hamburgers. Prices can
look a little over than moderate but portions are LARGE!
I can't provide you with the addresses, but the town is not large so you
can easily find them just walking around.
Have a nice trip.