Earthy mushrooms hold their own among a piquant red pepper relish — a riot of flavors. The relish’s base is known in Yoruba as ata din din, a condiment like sauce common throughout West Africa made from ground bell pepper, onions, chiles and sometimes tomatoes. Roast the mushrooms until lightly browned and crisp, as they absorb a lot more flavor when they’ve been slightly dehydrated. Pickled onion adds crunch and a hint of acid, and a scattering of fresh herbs gives it all a refreshing lightness, while being a pretty garnish. Serve over steamed rice and fried sweet plans, or reserve as a vegetable filling for moin moin.