channel from list of tuples

#!/user/bin/nextflow
nextflow.enable.dsl=2

process quast {

    input:
    tuple val(sample_id), path(contig)

    output:
    path "quast_directory_${sample_id}/report.tsv"

    """
    quast.py ${contig} -r reference_genome.fasta -o ${sample_id}_quast -t 4
    """
}

workflow {
    contig_ch = Channel.from( ['AH-806-L16', '/home/AH-806-L16_contigs.fasta'] )
    quast(contig_ch)