El Rosario spreads from the coast at Radazul and Tabaiba up to the forests around La Esperanza, and it's known across Tenerife for its guachinches. They serve typical Canarian food with home-made wine, a good match if you like traditional cooking and a decent glass.
Pork, chicken and rabbit are the mainstays, served with papas arrugadas, vegetables and other Canarian sides. Prices are reasonable, so a meal won't cost much.
If you're passing through El Rosario, stop at one of the local guachinches.