Grilled Portobello and Poblano Tacos. Grill 1# portobello mushrooms, 4 poblano peppers and 2 ears of corn. Caramelize 2 medium onions. Slice mushrooms into strips; stem, seed, remove skin and thinly slice poblanos into strips; cut corn off cobs. Toss grilled veggies with caramelized onions, until all is warmed through. Serve with cheese (feta here) and salsa.