Heat oven to 220C/200C fan/gas 7. Toss the onions in 1 tsp rapeseed oil and roast on a baking sheet for 10 mins. Coat the asparagus with the remaining oil and spread over another sheet. After 10 mins, add the asparagus to roast with the onions for 5 mins. Add the tomatoes and sunflower seeds and roast for 5 mins. The onions should be charred, the asparagus tender, the seeds toasted and the whole tomatoes near bursting.
Meanwhile, tip the bouillon and quinoa into a pan. Add 360ml water, cover and simmer for 20 mins until tender and the water has been absorbed. Whisk the tahini and lemon juice with 3 tbsp warm water, the garlic and tamari to make a dressing.
Pile the quinoa into bowls, top with rocket, spoon over half the dressing, add a pile of beans with the tomatoes, then a separate pile of the asparagus and onions. Spoon over the remaining dressing and scatter over the sunflower seeds. Will keep in the fridge for two days.