Well McDonalds and KFC are only just over the road!
Seriously, here are a few places I know not far from Solaqua. These are open all year and cater for locals not just tourists.
Cafe O Jorge, above the Pingo Doce supermarket by the 'Watches' roundabout. Excellent piri-piri chicken after around 7pm in the evenings. More of a working people's cafe in the daytime.
Alfredo's, along the road towards the old town but turn left at the Telecom shop. Good value for a 'proper' dinner.
Adega do David, up the hill about 50 metres from Alfredo's where a few of us had a very good piri piri chicken with chips and stuff plus beer for 9 Euros last week. Nice bar (Floyd's) next door as well!
Prazeres going down the Rua dos MFA into the old town, turn right at the bottom by the Geordi Viking bar and it's there.
O Valeiro and O Cateiro in the road to the tunnel. Both do an excellent fixed price tourist menu around 9 or 10 Euros plus set lunches for as little as 6 or 7.
Don't go near the places in the square where they chase after you with menus as you won't get change out of 20 Euros per head. Even more so, avoid the places right down on the seafront! If the Tex-Mex place just back from the beach is open, you can get some good deals there.
Hope that helps.