To a small saucepan, heat a teaspoon or two of olive oil, over high heat. When the oil is hot, add the peas and cook for 1 to 2 minutes, giving them a good shake once or twice, until their skins are blistered. To the jar of a blender, add the crushed cumin and coriander, blistered peas, garbanzo beans, lemon juice, tahini, garlic clove and a few pinches of salt. Pulse until chunky. With the machine running, pour in the reserved pea juice or a splash or two of warm water, adding a bit more if needed. Pulse until the hummus is smooth-ish. Give it a taste test and add a bit more salt, if you like.