A favorite accompaniment for couscous, harissa is also used to flavor soups, stews, salads, vegetables and egg dishes. Try it as a replacement for condiments like mustard if you like your sandwiches hot! This seasoning creates a bold and spicy rub for meats or try adding to olive oil and chopped garlic for a classic harissa paste. Blend with yogurt for a tangy dip. for vegetables. Add the spice to olive oil and chopped garlic for a classic harissa paste.